The Wayback Machine - https://web.archive.org/web/20200929074253/https://docs.github.com/en/enterprise-server@2.21/github/administering-a-repository/managing-branches-in-your-repository

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.