On refresh a page what process will be to do first ?

Question

When we refresh a page on the browser, what is the first will be process : browser check to its cache OR browser send request directly to the server, get response header from server than decide to load content from browser cache or from the server?
Since we can set header cache expiration , must revalidate, and/or must refresh on server side for a file/page.

Answer 1

I'm offline for a bit but just so you can look, this landed me in RFC 2616 section 13 (Caching in HTTP).

That doc is a guide and not much fun to read. Proxies, HTTP version and expire times complicate this a little, but you may have better luck looking at "304 Not Modified" in response to a "GET" with cached timestamp. Sorry I didn't have more time.