Found the answer. Application / server. Quote from Taylor:
In order to only instantiate the providers that are needed for a given request, Laravel generates a “service manifest” that is stored in the app/storage/meta directory. This manifest lists all of the service providers for the application, as well as the names of the container bindings they register. So, when the application asks the container for the queue container binding, Laravel knows that it needs to instantiate and run the QueueServiceProvider because it is listed as providing the queue service in the manifest. This allows the framework to lazy-load service providers for each request, greatly increasing performance.
When you add a service provider to the providers array, Laravel will automatically regenerate the service manifest file during the next request to the application