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.
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.
For greater collaboration, you can allow commits on branches you've created from forks. Permission to commit to your forked branches is limited to those with push access to the upstream repository of the fork.