Defining the mergeability of pull requests

Protected branches ensure that collaborators on your repository cannot make irrevocable changes to branches. Enabling protected branches also allows you to enable other optional checks and requirements, like required status checks and required reviews.

If you're a repository owner or have admin permissions in a repository, you can customize branch protections in the repository and enforce certain workflows, such as requiring more than one pull request review or requiring certain status checks to pass before allowing a pull request to merge.

Required status checks ensure that all required CI tests are passing before collaborators can make changes to a protected branch.

You can set up required status checks to either be "loose" or "strict." The type of required status check you choose determines whether your branch is required to be up to date with the base branch before merging.

Repository administrators can enforce required status checks before a branch is merged in a pull request or before commits on a local branch can be pushed to the protected remote branch.

Branches within repositories that belong to organizations can be configured so that only certain users or teams can push to the branch.

You can enforce branch restrictions so that only certain users or teams can push to a protected branch in repositories owned by your organization.

Required reviews ensure that pull requests have a specific number of approving reviews before collaborators can make changes to a protected branch.

Repository administrators can enforce required reviews so that pull requests must have a specific number of approving reviews before they are merged.

Required commit signing ensures that collaborators can only push verified signed commits to a protected branch.

Repository administrators can enforce required commit signing on a branch to block all commits that are not signed and verified.