Forks are often used in open source development on GitHub Enterprise.
A fork is a copy of a repository that you manage. Forks let you make changes to a project without affecting the original repository. You can fetch updates from or submit changes to the original repository with pull requests.
Sync a fork of a repository to keep it up-to-date with the upstream repository.
You must configure a remote that points to the upstream repository in Git to sync changes you make in a fork with the original repository. This also allows you to sync changes made in the original repository with the fork.
If you don't have push (write) access to an upstream repository, then you can pull commits from that repository into your own fork.
This article explains how deleting your repository or changing its visibility affects that repository's forks.