 Version-control commit

A version-control commit records an identifiable revision together with history metadata. In Git, a commit names a tree snapshot and parent commits, alongside author/committer information and a message. An initial commit has no parent; an ordinary commit has one, while a merge can have several.^[ref]

The parent links form a commit graph, allowing a tool to compare revisions and traverse ancestry. Rewriting a commit's recorded content or metadata creates a different commit object rather than silently modifying the old one. A commit identifies the recorded source snapshot; reproducing a calculation also requires external data, selected dependencies and execution settings that were not necessarily stored in that snapshot.