Git Internals

Commit Objects, Parents, and Messages

Show how commit objects connect trees, parent commits, and messages into the history graph.

The short version

Show how commit objects connect trees, parent commits, and messages into the history graph.

Key ideas

  • Commit objects contain tree, parent, author, and message data
  • Parent links shape the commit graph
  • The commit message is part of the object content

Why this helps you understand commands

Many command differences that feel arbitrary become easier once you see how Git is updating objects, refs, the index, or reachability.

Suggested follow-up

It pairs well with git show, git log --graph, git cat-file, git rev-parse, or git fetch.

Related Reads

Git Object Database

Understand blob, tree, commit, and tag objects, and why Git describes itself as a content-addressable object database.

Working Tree, Index, and Object Store

Separating the working tree, index, and object database is the clearest way to understand add, commit, restore, and reset.

Git References and HEAD

Put branches, tags, remote-tracking refs, and HEAD into one model so Git's pointer behavior becomes easier to reason about.

PreviousBlob Objects and Content Addressing

Explain how blobs store raw content and why hashes become the identity of Git objects.

NextRefspecs and Ref Updates

Explain how refspecs determine which refs are mapped and updated during fetch and push.