Concepts

jjforge shows Jujutsu (jj) repositories. Most people arrive knowing git, so this page maps each jj concept to its closest git equivalent, says where the analogy breaks, and says what that means for the UI. The jj documentation covers the concepts in depth.

jj concept	Closest git equivalent	Where the analogy breaks	What it means for the UI
Change	Commit	A change keeps its identity when it is rewritten. Each rewrite produces a new commit.	The change is the unit the UI shows, links to, and reviews. There is no pull request object.
Change ID	Commit hash	The change ID is stable across rewrites. The commit ID changes with every rewrite.	Change IDs lead and link. Commit IDs are secondary detail.
Working-copy commit	Index and working tree	jj records the working copy as a commit. There is no staging area.	The server has no working copy, so the UI never shows @.
Bookmark	Branch	A bookmark doesn’t move when a new change is made on top of it. It moves only when set or pushed.	Call it a bookmark, never a branch. Show where each one points.
Trunk	main	trunk() is a revset that names the main bookmark, not a special branch.	Trunk is the default revision and the landing target.
Operation log	Reflog	The operation log records every change to the whole repository, and any operation can be undone.	Show operations as history of the repository, each with its principal.
Conflict	Merge conflict	A conflict is stored in a commit and doesn’t block work. It can be resolved later.	A conflicted change is a normal state. Mark it and list the conflicted files.
Divergent change	None	Two commits can share one change ID after concurrent rewrites.	Show every commit of a divergent change, and never pick one in silence.
Evolution	Reflog of one branch	The evolution log lists every earlier version of one change.	A change page links to its earlier versions.
Revset	Revision range (a..b)	A revset is a small query language: trunk()..@, author(alice), conflicts().	Accept revisions in the address, and report an ambiguous one with its candidates.
Stack	A branch of dependent commits	A stack is a chain of changes. Rewriting one rebases the rest automatically.	Review and landing work on stacks, not on single branches.
Colocated repository	A git repository	jj and git share one .git directory, so git tools keep working.	Clone instructions work for both jj and git.