Managing branches in your repository
Whenever you propose a change in Git, you create a new branch. Branch management is an important part of the Git workflow. After some time, your list of branches may grow, so it's a good idea to delete merged or stale branches.
Branches are central to collaboration on GitHub, and the best way to view them is the branches page.
You can change the name of a branch in a repository.
If you have more than one branch in your repository, you can configure any branch as the default branch.
If you have write access in a repository, you can delete branches that are associated with closed or merged pull requests. You cannot delete branches that are associated with open pull requests.