Cache-Control Directives
The `Cache-Control` header defines cache settings:
- `no-store`: Instructs browsers never to save the resource.
- `no-cache`: Instructs browsers to validate changes with the server before reuse.
- `public, max-age=31536000`: Allows browsers and CDNs to cache the asset for 1 year.
HTTP Snippet
http
HTTP/1.1 200 OK
Cache-Control: public, max-age=31536000, immutable
ETag: "w/33a64df551425f1b"ETags and Conditional Requests
An ETag is a unique hash representing a file's contents. If a cached file is expired, the browser sends the ETag in the `If-None-Match` header. If the file hasn't changed, the server returns status 304 (Not Modified) without sending the payload, saving bandwidth.