The publish mode determines if publish is a direct merge or a pull request. Merges have less overhead, while pull requests can link to external builds, checks and workflows.
To change the publish mode for a Git connected site:
Pull requests provide an intermediate step for publishing, where external services connected to the GitHub Status API (if using GitHub) check the changes pass your requirements.
Any pull requests that are not from the connected branch to publish branch are hidden in CloudCannon.
The workflow with this publish mode is:
Merge publishes the changes into the publish branch, while Close cancels the pull request. Changes made are not reversed after closing a pull request.
You can choose to delete the site associated with the development branch after publishing. This is useful if you know that no further development will take place on that branch after it is merged.
To turn this feature on, go to Site Settings / Files / Publishing and click the checkbox labelled Delete this site after publish.