Meaning of Internet error codes

Often browsing the internet and trying to open any website, e-mail or any FTP sites , we see different error codes there.
But we are wondering what these error codes means? So now I am providing some error codes with their meaning!
It also help you to rectify these error
→ Error Code 400 meaning “This is bad request error”
In this case First check URL name, you may be typing wrong URL name and server could not understand your request.
→ Error code 401 meaning “unauthorized access site or page”.
In this case check your username and password if you are trying to open any webpage.
→ Error code 402 meaning “Payment Required”
→ Error code 403 meaning You are trying to open any forbidden page and you are blocked by that domain.
→ Error code404 meaning Here you are trying to open the webpage that was removed or re-named, also check the URL spelling.
→ Error code 408 meaning “time out error”. you should send the request with in time that the server set for you.