304

Not Modified

The client has asked for a resource that the server deems to be not required to re-transmitted as it has not changed since the last time the client had asked for it. This happens only in GET, HEAD and OPTIONS requests.

Use Case

A browser has asked for a webpage like google.com and it got the response. 10 seconds later, the page was reloaded by the user and the response is a 304 code, meaning the browser can use the previously sent response as the resource hasn't been changed since.