Too Long; Didn't Read
The most recent commit on a branch is referred to as the tip of that branch. Branches are dynamic and code can be added to them. A tag is most typically used to mark a particular point in the commit ancestry chain. A branch is an active line of development whereas a tag is a reference to a specific commit on any branch. The tip of the branch is referenced by a branch head, which moves forward as additional development is done on the branch. A single git repository can track an arbitrary number of branches, but your working tree is associated with one of them.