By Hemanta Sundaray on 2021-05-21
Status codes are issued by a server in response to a client's request made to the server. They indicate whether a specific HTTP request has been successfully completed or not.
Responses are grouped in five classes:
The request was fulfilled.
The 4xx codes are intended for cases in which the client seems to have erred, and the 5xx codes are intended for cases in which the server is aware that the server has erred.
The server could not understand the request due to invalid syntax.
This response means “unauthenticated”. That is the client must authenticate itself to get the requested response.
The client identity is known to the server but the client does not have access rights to the content, that is, the server is refusing to give the requested resource.
The server can not find the requested resource. In the browser, this means the URL is not recognized. In an API, this can also mean that the endpoint is valid but the resource itself does not exist. Servers may also send this response instead of 403 to hide the existence of a resource from an unauthorized client. This response code is probably the most famous one due to its frequent occurrence on the web.
The server encountered an unexpected situation it does not know how to handle.