HTTP status codes tutorial

If you delete your internet explorer cache, open the f12 tools  (by pressing F12 key) and then try to visit www.google.com, this is what you see in the f12 tool

So this is what happens, since you cleared the cache, the browser gets all the resources from server. The 200 (inside the red box) that you see in the result column, means the fetch was successful. This HTTP status code is a part of the response header.

Now if you refresh the page, this is what you see,

Notice that the HTTP status codes for all the image and javascript resources has a status code of 304. What this means is that this resource has not changed since it was last requested. When the browser gets this message, it loads this resource from the browser cache.

A complete list of HTTP status code can be found here. 

Status codes are classified into the following categories.

Range	What it means
100-199	Information
200-299	Some success message
300-399	Some form of redirection
400-499	Client made a bad request
500-599	There was some error at the webserver

These are the most common status codes you would come across

Status code	Meaning
200	The request has succeeded
304	Resource not modified since the last fetch.
404	Not found