Git 03: Commits, Refs and HEAD

The board where “rollback = git revert” and “audit = git log” sit in one corner as if they were obvious. Both depend on what this stage builds: a commit that remembers its parent, and a name that moves.

Before you start. Git 02: The Tree turned a folder into one top hash: blobs for files, trees for folders, every tree named by its contents. A tree is a snapshot with no story. This stage adds the story. You need nothing else, but the user-side view of commits and branches in Git: the ledger every change signs (commits, branches, merge and rebase) makes a good companion.