HTTP status codes play a vital role in communicating between clients and servers. Understanding these codes is essential for web developers and administrators to troubleshoot problems and ensure the smooth operation of web applications. HTTP status codes are a crucial aspect of the Internet, which allows communication between clients (such as web browsers) and servers. These codes provide a standardized way of communicating the outcome of a request made by a client to a server. The status codes are three-digit numbers that are embedded in the HTTP header of a web page response. They indicate the status of the request, whether it was successful or not, and why it failed, if applicable. These codes are defined by the W3C, which is responsible for developing and maintaining web standards. The codes are grouped into five classes i.e. Informational class, Success class, Redirection class, Client Error class, and Server Error class.

There are five types of HTTP status codes. Each class has its own three-digit code.
  • 1xx (Informational): The request has been received and is being processed by the server.
  • 2xx (Successful): The request was received successfully, understood, and accepted.
  • 3xx (Redirection): The client must complete the request by taking additional actions.
  • 4xx (Client error): The request has bad syntax and cannot be fulfilled by the server.
  • 5xx (Server error): A valid request was not fulfilled by the server.
Here are some of the most common HTTP status codes:
  • 200 OK: The request was accepted and the server has sent the requested data.
  • 301 Permanently Moved: The requested resource was permanently moved to a different URL.
  • 404 Not Found: The requested resource couldn't be found on the server.
  • 500 Internal Server Error - An error occurred while processing the request.
BY Best Interview Question ON 07 Apr 2023