GIT is a Distributed Version Control System (DVCS) that was "born" for Linux kernel development. It's not the easiest to use for novices, but it fast and allows to create advanced code sharing scenarios.
Sometimes you want to share locally created GIT branch with other developers (code review, collaborative development on branch, etc). You can do it easily by issuing a command:
$ git push origin local_branch_name
If you decide to drop remote branch just issue:
$ git push origin :local_branch_name