Response codes are standardized numerical codes used in computer networking and web development to indicate the status of a request made to a server. These codes help users and developers understand whether a request was successful, encountered an error, or requires further action. Common examples include 200 for a successful request, 404 for a page not found, and 500 for a server error. These codes are part of the HTTP protocol, which governs how messages are formatted and transmitted on the web. Each response code falls into a specific category, such as informational, success, redirection, client error, or server error, making it easier to diagnose issues and improve user experience.