Caching from a server's point of view is intimately linked to client-side caching in the browser. In addition to storing resources on the server, the headers that you set will be used to control caches everywhere.
The HTTP headers that you set are used by both proxy servers and browsers, including not only standard browsing, but also fetching from a service worker. For example, if the Cache-Control header specifies no-store, then you won't be able to add the resource to a cache from your worker.
