Diagrams: Git

This document is part of the Git workshop and describes diagrams as training material, reference documentation and review basis.

Target State

You should not operate Git as a dangerous command list. The useful model is state: working tree, index, commit graph, references, remotes and local recovery paths. The document connects concept, workflow, evidence and safe return paths.

Focus

Working Tree zu Index
Commit-Graph
Merge
Rebase
Remote-Synchronisation

Core Terms

Term	Meaning
`Repository`	Database of objects, references, configuration and working tree relationship for project history.
`Working Tree`	Checked-out files that you read, edit and compare against index and HEAD.
`Index`	Staging area between working tree and commit; it defines the next snapshot.
`Commit`	Immutable snapshot with parents, author, committer, message and tree object.
`HEAD`	Pointer to the currently checked-out commit or current branch reference.
`Branch`	Movable reference to a commit, usually under `refs/heads/`.
`Tag`	Reference to a specific state, lightweight or annotated and optionally signed.
`Remote`	Named connection to another repository with fetch and push URLs.
`Refspec`	Rule that defines which references are transferred or updated during fetch or push.
`Merge`	Integration of histories through a merge commit or fast-forward.
`Rebase`	Replay of a commit series onto another base; changes commit IDs.
`Reflog`	Local log of reference movements, useful for recovery.
`Hook`	Local or server-side script executed on specific Git events.
`Submodule`	Reference to another repository at a specific commit inside a superproject.
`Credential Helper`	Mechanism Git uses to ask for, cache or retrieve credentials from secure storage.
`Object Database`	Storage for blobs, trees, commits and tags, addressed by object IDs.

Working Model

Check context first: current branch, HEAD, working tree, index and remote-tracking branches.
State whether you want to change files, index, commit graph, references or remotes.
Execute the smallest matching change and record the command.
Prove state with git status, git diff, git log, git show, git branch -vv, git remote -v or git reflog.
Assess whether the change is only local, visible in a shared branch or already published.
Choose recovery commands only after that classification.

Reference Commands

# Check context and configuration
git --version
git config --list --show-origin
git status --short --branch

# Understand changes
git diff
git diff --staged
git log --oneline --graph --decorate --all

# Work safely
git add <path>
git commit -m "Describe the functional change"
git switch -c feature/<topic>
git merge --no-ff feature/<topic>

# Recovery and diagnosis
git reflog
git restore <path>
git restore --staged <path>
git merge --abort
git rebase --abort

Typical Decisions

Decision	Useful Question	Risk of the Wrong Choice
`restore`, `reset` or `revert`	Is the target working tree, index, local history or shared history?	data loss, confusing team history or unnecessary conflicts
Merge or rebase	Should the original branch point remain visible?	changed commit IDs in shared branches
Annotated or lightweight tag	Should a release carry traceable metadata?	unclear release provenance
Credential helper	Where are credentials stored and how are they protected?	plaintext tokens or long-lived secrets
Submodule or another model	Must another repository be pinned to an exact commit?	hard-to-maintain dependencies and forgotten updates
Local or server-side hook	Is this convenience or enforceable governance?	false confidence without enforcement

Operations Notes

Git stores snapshots and references; it is not a central server service.
Many seemingly destructive local states can be recovered with reflog as long as garbage collection has not removed objects.
git credential-store stores credentials unencrypted on disk; accept that only with deliberate risk analysis.
Rebase and history rewrite are useful locally but team-critical in shared branches.
Repository hooks are not automatically trusted or globally enforced; server-side rules require platform support.

Scope Boundary

This document covers core Git functionality. Hosting platforms, pull requests, issues, Actions, GitLab CI or GitHub Advanced Security are mentioned only as adjacent practice.

Practice Appendix: Diagrams

This appendix provides a backlog for longer trainings, reviews and repetition. Each task is small enough to reproduce in a local lab repository.

A001. Working Tree zu Index

Task: document context and desired state and explicitly relate the observation to Working Tree zu Index.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A002. Commit-Graph

Task: explain index state and explicitly relate the observation to Commit-Graph.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A003. Merge

Task: read the commit graph and explicitly relate the observation to Merge.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A004. Rebase

Task: assess diff and patch and explicitly relate the observation to Rebase.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A005. Remote-Synchronisation

Task: check remote relationship and explicitly relate the observation to Remote-Synchronisation.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A006. Repository

Task: isolate conflict cause and explicitly relate the observation to Repository.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A007. Working Tree

Task: use reflog as recovery path and explicitly relate the observation to Working Tree.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A008. Index

Task: name history rewrite risk and explicitly relate the observation to Index.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A009. Commit

Task: assess credential impact and explicitly relate the observation to Commit.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A010. HEAD

Task: describe signature or hook boundary and explicitly relate the observation to HEAD.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A011. Branch

Task: write down rollback or recovery path and explicitly relate the observation to Branch.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A012. Tag

Task: state a team rule and explicitly relate the observation to Tag.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A013. Remote

Task: document context and desired state and explicitly relate the observation to Remote.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A014. Refspec

Task: explain index state and explicitly relate the observation to Refspec.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A015. Merge

Task: read the commit graph and explicitly relate the observation to Merge.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A016. Rebase

Task: assess diff and patch and explicitly relate the observation to Rebase.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A017. Reflog

Task: check remote relationship and explicitly relate the observation to Reflog.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A018. Hook

Task: isolate conflict cause and explicitly relate the observation to Hook.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A019. Submodule

Task: use reflog as recovery path and explicitly relate the observation to Submodule.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A020. Credential Helper

Task: name history rewrite risk and explicitly relate the observation to Credential Helper.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A021. Object Database

Task: assess credential impact and explicitly relate the observation to Object Database.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A022. Working Tree zu Index

Task: describe signature or hook boundary and explicitly relate the observation to Working Tree zu Index.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A023. Commit-Graph

Task: write down rollback or recovery path and explicitly relate the observation to Commit-Graph.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A024. Merge

Task: state a team rule and explicitly relate the observation to Merge.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A025. Rebase

Task: document context and desired state and explicitly relate the observation to Rebase.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A026. Remote-Synchronisation

Task: explain index state and explicitly relate the observation to Remote-Synchronisation.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A027. Repository

Task: read the commit graph and explicitly relate the observation to Repository.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A028. Working Tree

Task: assess diff and patch and explicitly relate the observation to Working Tree.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A029. Index

Task: check remote relationship and explicitly relate the observation to Index.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A030. Commit

Task: isolate conflict cause and explicitly relate the observation to Commit.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A031. HEAD

Task: use reflog as recovery path and explicitly relate the observation to HEAD.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A032. Branch

Task: name history rewrite risk and explicitly relate the observation to Branch.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A033. Tag

Task: assess credential impact and explicitly relate the observation to Tag.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A034. Remote

Task: describe signature or hook boundary and explicitly relate the observation to Remote.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A035. Refspec

Task: write down rollback or recovery path and explicitly relate the observation to Refspec.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A036. Merge

Task: state a team rule and explicitly relate the observation to Merge.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A037. Rebase

Task: document context and desired state and explicitly relate the observation to Rebase.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A038. Reflog

Task: explain index state and explicitly relate the observation to Reflog.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A039. Hook

Task: read the commit graph and explicitly relate the observation to Hook.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A040. Submodule

Task: assess diff and patch and explicitly relate the observation to Submodule.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A041. Credential Helper

Task: check remote relationship and explicitly relate the observation to Credential Helper.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A042. Object Database

Task: isolate conflict cause and explicitly relate the observation to Object Database.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A043. Working Tree zu Index

Task: use reflog as recovery path and explicitly relate the observation to Working Tree zu Index.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A044. Commit-Graph

Task: name history rewrite risk and explicitly relate the observation to Commit-Graph.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A045. Merge

Task: assess credential impact and explicitly relate the observation to Merge.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A046. Rebase

Task: describe signature or hook boundary and explicitly relate the observation to Rebase.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A047. Remote-Synchronisation

Task: write down rollback or recovery path and explicitly relate the observation to Remote-Synchronisation.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A048. Repository

Task: state a team rule and explicitly relate the observation to Repository.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A049. Working Tree

Task: document context and desired state and explicitly relate the observation to Working Tree.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A050. Index

Task: explain index state and explicitly relate the observation to Index.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A051. Commit

Task: read the commit graph and explicitly relate the observation to Commit.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A052. HEAD

Task: assess diff and patch and explicitly relate the observation to HEAD.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A053. Branch

Task: check remote relationship and explicitly relate the observation to Branch.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A054. Tag

Task: isolate conflict cause and explicitly relate the observation to Tag.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A055. Remote

Task: use reflog as recovery path and explicitly relate the observation to Remote.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A056. Refspec

Task: name history rewrite risk and explicitly relate the observation to Refspec.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A057. Merge

Task: assess credential impact and explicitly relate the observation to Merge.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A058. Rebase

Task: describe signature or hook boundary and explicitly relate the observation to Rebase.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A059. Reflog

Task: write down rollback or recovery path and explicitly relate the observation to Reflog.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A060. Hook

Task: state a team rule and explicitly relate the observation to Hook.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A061. Submodule

Task: document context and desired state and explicitly relate the observation to Submodule.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A062. Credential Helper

Task: explain index state and explicitly relate the observation to Credential Helper.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A063. Object Database

Task: read the commit graph and explicitly relate the observation to Object Database.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A064. Working Tree zu Index

Task: assess diff and patch and explicitly relate the observation to Working Tree zu Index.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A065. Commit-Graph

Task: check remote relationship and explicitly relate the observation to Commit-Graph.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A066. Merge

Task: isolate conflict cause and explicitly relate the observation to Merge.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A067. Rebase

Task: use reflog as recovery path and explicitly relate the observation to Rebase.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A068. Remote-Synchronisation

Task: name history rewrite risk and explicitly relate the observation to Remote-Synchronisation.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A069. Repository

Task: assess credential impact and explicitly relate the observation to Repository.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A070. Working Tree

Task: describe signature or hook boundary and explicitly relate the observation to Working Tree.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A071. Index

Task: write down rollback or recovery path and explicitly relate the observation to Index.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A072. Commit

Task: state a team rule and explicitly relate the observation to Commit.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A073. HEAD

Task: document context and desired state and explicitly relate the observation to HEAD.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A074. Branch

Task: explain index state and explicitly relate the observation to Branch.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A075. Tag

Task: read the commit graph and explicitly relate the observation to Tag.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A076. Remote

Task: assess diff and patch and explicitly relate the observation to Remote.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A077. Refspec

Task: check remote relationship and explicitly relate the observation to Refspec.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A078. Merge

Task: isolate conflict cause and explicitly relate the observation to Merge.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A079. Rebase

Task: use reflog as recovery path and explicitly relate the observation to Rebase.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A080. Reflog

Task: name history rewrite risk and explicitly relate the observation to Reflog.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A081. Hook

Task: assess credential impact and explicitly relate the observation to Hook.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A082. Submodule

Task: describe signature or hook boundary and explicitly relate the observation to Submodule.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A083. Credential Helper

Task: write down rollback or recovery path and explicitly relate the observation to Credential Helper.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A084. Object Database

Task: state a team rule and explicitly relate the observation to Object Database.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A085. Working Tree zu Index

Task: document context and desired state and explicitly relate the observation to Working Tree zu Index.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A086. Commit-Graph

Task: explain index state and explicitly relate the observation to Commit-Graph.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A087. Merge

Task: read the commit graph and explicitly relate the observation to Merge.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

A088. Rebase

Task: assess diff and patch and explicitly relate the observation to Rebase.
Evidence: Write down at least one Git command, one expected result and one limit of that evidence.
Team question: What coordination is required before this change lands in a shared branch?
Security question: Which credentials, signatures, hooks or confidential files could be affected?
Recovery: Explain whether reflog, restore, reset, revert, merge --abort, rebase --abort or a backup is the right path.

Official Sources and Scope

The material is aligned with public Git documentation. GitHub, GitLab, Forgejo and other hosting platforms are mentioned only where they explain common Git workflows; they are not the same thing as Git itself.

Git Reference: https://git-scm.com/docs
Git Manual: https://git-scm.com/docs/git
Pro Git Book: https://git-scm.com/book/en/v2
git-submodule: https://git-scm.com/docs/git-submodule
gitcredentials: https://git-scm.com/docs/gitcredentials
git-credential-store: https://git-scm.com/docs/git-credential-store
GitHub Certifications: https://docs.github.com/en/get-started/showcase-your-expertise-with-github-certifications/about-github-certifications
GitHub Foundations on Microsoft Learn: https://learn.microsoft.com/en-us/credentials/certifications/github-foundations/

Additional Review Drills

Use these drills when the primary task is complete and the learner needs another pass over operational reasoning. They are intentionally evidence-oriented and can be answered in a local lab repository.

Drill 01: working tree

State which Git state or reference is affected by working tree.
Name one command that produces evidence and one field or line in the output that matters.
Explain what can be concluded from that evidence and what cannot be concluded from it.
Describe the safest recovery path for a shared training repository.

Drill 02: index

State which Git state or reference is affected by index.
Name one command that produces evidence and one field or line in the output that matters.
Explain what can be concluded from that evidence and what cannot be concluded from it.
Describe the safest recovery path for a shared training repository.

Drill 03: commit graph

State which Git state or reference is affected by commit graph.
Name one command that produces evidence and one field or line in the output that matters.
Explain what can be concluded from that evidence and what cannot be concluded from it.
Describe the safest recovery path for a shared training repository.

Drill 04: branch reference

State which Git state or reference is affected by branch reference.
Name one command that produces evidence and one field or line in the output that matters.
Explain what can be concluded from that evidence and what cannot be concluded from it.
Describe the safest recovery path for a shared training repository.

Drill 05: remote-tracking branch

State which Git state or reference is affected by remote-tracking branch.
Name one command that produces evidence and one field or line in the output that matters.
Explain what can be concluded from that evidence and what cannot be concluded from it.
Describe the safest recovery path for a shared training repository.

Drill 06: reflog

State which Git state or reference is affected by reflog.
Name one command that produces evidence and one field or line in the output that matters.
Explain what can be concluded from that evidence and what cannot be concluded from it.
Describe the safest recovery path for a shared training repository.

Drill 07: credential helper

State which Git state or reference is affected by credential helper.
Name one command that produces evidence and one field or line in the output that matters.
Explain what can be concluded from that evidence and what cannot be concluded from it.
Describe the safest recovery path for a shared training repository.

Drill 08: signature

State which Git state or reference is affected by signature.
Name one command that produces evidence and one field or line in the output that matters.
Explain what can be concluded from that evidence and what cannot be concluded from it.
Describe the safest recovery path for a shared training repository.

Drill 09: hook

State which Git state or reference is affected by hook.
Name one command that produces evidence and one field or line in the output that matters.
Explain what can be concluded from that evidence and what cannot be concluded from it.
Describe the safest recovery path for a shared training repository.

Drill 10: submodule

State which Git state or reference is affected by submodule.
Name one command that produces evidence and one field or line in the output that matters.
Explain what can be concluded from that evidence and what cannot be concluded from it.
Describe the safest recovery path for a shared training repository.

Drill 11: tag

State which Git state or reference is affected by tag.
Name one command that produces evidence and one field or line in the output that matters.
Explain what can be concluded from that evidence and what cannot be concluded from it.
Describe the safest recovery path for a shared training repository.

Drill 12: recovery

State which Git state or reference is affected by recovery.
Name one command that produces evidence and one field or line in the output that matters.
Explain what can be concluded from that evidence and what cannot be concluded from it.
Describe the safest recovery path for a shared training repository.

Drill 13: working tree

State which Git state or reference is affected by working tree.
Name one command that produces evidence and one field or line in the output that matters.
Explain what can be concluded from that evidence and what cannot be concluded from it.
Describe the safest recovery path for a shared training repository.

Drill 14: index

State which Git state or reference is affected by index.
Name one command that produces evidence and one field or line in the output that matters.
Explain what can be concluded from that evidence and what cannot be concluded from it.
Describe the safest recovery path for a shared training repository.

Drill 15: commit graph

State which Git state or reference is affected by commit graph.
Name one command that produces evidence and one field or line in the output that matters.
Explain what can be concluded from that evidence and what cannot be concluded from it.
Describe the safest recovery path for a shared training repository.

Drill 16: branch reference

State which Git state or reference is affected by branch reference.
Name one command that produces evidence and one field or line in the output that matters.
Explain what can be concluded from that evidence and what cannot be concluded from it.
Describe the safest recovery path for a shared training repository.