A git merge combines two branches of development history into a single branch within a Git repository. Git supports two merge strategies: fast-forward merges (when the target branch is a direct ancestor of the source, so the pointer advances without creating a new commit) and three-way merges (when both branches have diverged from a common ancestor). Three-way merges use the common ancestor to determine which changes to apply automatically and produce a new merge commit with two parents. Merge conflicts occur when the same region of a file was modified in both branches; these require manual resolution before the merge can complete. In an Agential Semioverse Repository, merges represent the composition of concurrent agent work: two agents operating on disjoint file regions produce commits that merge cleanly, while overlapping edits may conflict and require human adjudication.