I think of a git repo as a gigantic bramble bush, with some of the brambles joining back into each other. There are some labels attached to the bramble bush in

I think of a git repo as a gigantic bramble bush, with some of the brambles joining back into each other. There are some labels attached to the bramble bush in various places. Some of the labels follow the tips as they grow, some stay fixed. It gets interesting when you compare two bramble bushes with the same provenance, see how they differ, and then how they can be reconciled.