Which of the following describes a 404 error?

A 404 error is an HTTP response status code indicating that the server was unable to find the requested resource. When a user tries to access a specific page or resource on a web server and receives a 404 error, it means that the server searched for the resource (such as a webpage or an API endpoint) but could not locate it at the specified URL. This can happen for various reasons, such as the resource being moved, deleted, or never existing in the first place.

This status code is a standard part of the HTTP protocol and is crucial for web development and API management, as it helps developers troubleshoot issues with resource availability. The clarity of a 404 error response improves user experience by informing users that the requested content is not available rather than leaving them with no feedback at all.