The matchAll() method of the Clients interface returns a Promise for a list of service worker clients. Include the options parameter to return all service worker clients whose origin is the same as the associated service worker's origin. If options are not included, the method returns only the service worker clients controlled by the service worker.
The parameter passed into the oninstall handler, the InstallEvent interface represents an install action that is dispatched on the ServiceWorkerGlobalScope of a ServiceWorker. As a child of ExtendableEvent, it ensures that functional events such as FetchEvent are not dispatched during installation.
The Navigator.serviceWorker read-only property returns the ServiceWorkerContainer object for the associated document, which provides access to registration, removal, upgrade, and communication with the ServiceWorker.