404 and 503

[skiwee]

what is 404 and 503 error ?

[jackar56]

404 or not found error message is generated by the website hosting server when a user attempts to follow a broken or dead link. In other words this error code indicates that the client (user) was able to communicate with the server but the server could not find what was requested.
503 or bad gateway error is occurs when the server was acting as a gateway or proxy and it received an invalid response from the upstream server it accessed to fulfill the request.