Cache-Control: no-cache
is generally used in a request header (sent from web browser to server) to force validation of the resource in the intermediate proxies.
If the client doesn’t send this request to the server, intermediate proxies will return a copy of the content if it is fresh (has not expired according to Expire
or max-age
fields). Cache-Control
directs these proxies to revalidate the copy even if it is fresh.