Sometimes when you enter a URL in the address bar and try to open then you may have seen a message saying 404 Error or Not Found. This is an HTTP error message and is basically a standard response code from HTTP server. The message indicates that the URL request was sent to the server from the client but the server was unable to open it. The 404 error message is different from the Server not found error code. In the latter, the client’s request is not sent to the server.
When you get a 404 error code then it may simply imply that the requested URL is not available temporarily. You may however try opening it again and may be able to open it. The error can appear if the client has mistyped the URL. If the message says ‘Not found’ then the server may not have been able to find the URL but when it says Error 404 their may be an error from the user’s end. Sometimes the HTML page may mention Error 404 and Not Found as well. In such case the possible reasons are mentioned so that you can check and search for the URL again.