If you have a branch checked out and then add a commit, the branch had better "move" to point to the new commit, else you'd have to more work than merely `git c

If you have a branch checked out and then add a commit, the branch had better "move" to point to the new commit, else you'd have to more work than merely `git commit` -- work that's easy to forget, leaving you with orphaned commits that can be garbage collected, and which can be hard to find so you can update the branch pointer.