HTTP status code
Communication between web browsers and web servers takes place via the http protocol, whereby the browser makes a request to the web server that the latter provide it with a specific web page as an HTML document. The web server then sends the document it has received to the browser with an HTTP status code. The HTTP status code indicates whether the request was successful or unsuccessful. In both cases, the HTTP status code contains detailed information about the transmission.
HTTP status codes are three- digit numbers between 100 and 599, divided into five groups, which indicate the status of the connection. Group 1xx status codes concern general information such as "the request is still being processed," or"loadingtimeout." Group 2xx status codes are about the execution of processing. Typical messages of this status group are "the request was successfully processed" or "the client should rebuild the document." The status codes of group 3xx are about forwarding the request to other Internet addresses. These status codes are used to ensure successful processing.
HTTP status codes 4xx are about client errors that may occur during a request. These include Bad Request for an incorrect request, Error 404 Not Found for a resource not found, or Method not Allowed for requests that may only be made using other http methods. The last status code group, 5xx, deals with server errors, but these cannot be clearly separated from client errors. The 5xx status codes include Internal Server Error, Bad Gateway, Service Unavailable.