HTTP status codes are standardized responses given by web servers to indicate the outcome of a client's request to the server. They are part of the HTTP/1.1 standard and are classified into five categories based on the first digit of the status code. These categories include informational responses (100-199), successful responses (200-299), redirection messages (300-399), client error responses (400-499), and server error responses (500-599). Each code provides specific information about the status of the request.
For instance, a "200 OK" status code indicates that the request was successful and the server has returned the requested resource. On the other hand, a "404 Not Found" status code signifies that the server could not find the requested resource. "500 Internal Server Error" indicates a generic error on the server side, often due to an unexpected condition or misconfiguration. Understanding these status codes is crucial for debugging web applications and ensuring proper communication between clients and servers, as they provide insight into what went right or wrong with a request and help guide the appropriate response or corrective action.
The 1xx (Informational) class of status codes indicates that the request was received and understood, and that the server is continuing the process. These codes are provisional responses and provide information about the status of the server or request processing. They signal that the server is still working on the request and has not yet completed it.
2xx status codes indicate successful responses from a server to a client's request. These codes signify that the request was received, understood, and processed successfully.
HTTP 3xx status codes indicate redirection. They tell the client that the resource they are requesting is temporarily or permanently located elsewhere, and the client should follow the redirect.
4xx status codes indicate client errors, meaning the request contains incorrect syntax, cannot be fulfilled due to client actions, or lacks authentication.
The 5xx status codes indicate that the server encountered an unexpected condition that prevented it from fulfilling the request.