FPM is a process manager to manage the FastCGI SAPI (Server API) in PHP. Basically, it replaces the need for SpawnFCGI. It spawns the FastCGI children adaptively. This service is not working by default and you would need to enable it for your domains using a different tool we will be discussing in a separate tutorial.
When on the page, you will be presented with a question “Are you sure you wish to restart this service?” In order to restart it, click the “Yes” button. This will take you to the changelog page, informing you that the service has been restarted.