Common Internet Errors

Error 400 - Bad Request (error is simply a bad request error, as you might be typing some unknown URL that server could not understand, so make sure that URL you are typing is write).
Error 401 - Unauthorized Request (If you try to access some unauthorized website than you might see this 401 error, so make sure you have entered correct username and password).
Error 402 - (error is specified for any kind of payment errors you receive, so if you attempting any transaction and you forgot to add payment information than you might face this error).
Error 403 - Forbidden (error can cause if you are accessing any forbidden page s its somewhat similar to 401 error, so make sure you are not blocked by that website).
Error 404 - Not Found (is the most common and most recognized error, so its like most website have this error, so that website might be removed or re-named so make sure spellings are good).
Error 408 - (error is the timeout error, so if you are on some page where it requires you to add something in specified time and you do not do that than you might face this 408 error).
Error 500 - Internal Error.
Error 501 - Not Implemented.
Error 502 - Bad Gateway.
Error 503 - Service Unavailable.
Error 504 - Gateway Time-Out.
Error 505 - HTTP Version not supported/ DNS Lookup Fail/unknown host.
 
Error 500-599 - Server Errors.