A 404 error is a Hypertext Transfer Protocol (HTTP) standard response code that occurs when a server cannot find the requested page.
This error message indicates that the client could reach the server, but the server could not find the requested page. Often, this is due to a broken or dead link, or the page has been moved or deleted.
Websites can customize their 404 error page to provide a better user experience, offering links to home pages or search functions, and sometimes incorporating creative or humorous design elements. Proper handling of 404 errors is important for website navigation and SEO performance.