You see the Git documentation saying things like
The branch must be fully merged in HEAD.
But what is Git HEAD
exac
After reading all of the previous answers, I still wanted more clarity. This blog at the official git website http://git-scm.com/blog gave me what I was looking for:
The HEAD in Git is the pointer to the current branch reference, which is in turn a pointer to the last commit you made or the last commit that was checked out into your working directory. That also means it will be the parent of the next commit you do. It's generally simplest to think of it as HEAD is the snapshot of your last commit.