commit is snapshot of all filesnot a change set to store the hash ID of the latest commit in a branch name.branch name is just the lastest hash of commi branch name is just the lastest hash of commitIn fact, this is the very definition of a branch name: a name like master simply stores the hash ID of the commit we want to call the latest for that branch. So given the A--B--C string of commits, we just add the name master, pointing to commit C:To remember which branch...