404, commonly referred to as "Error 404" or simply "404," is an HTTP status code that indicates the failure of a client to communicate effectively with a server or to retrieve a specific web resource. It is an error message related to the World Wide Web (WWW) and is widely recognized as the standard for page not found errors.
When a user requests a webpage or resource that cannot be found, the server responds with a 404 status code. This error message signifies that the requested resource is unavailable, as it may have been moved, deleted, or simply does not exist. Typically, this results from users clicking on broken or outdated links, mistyping URLs, or the website changing its structure.
The number "404" originates from the Hypertext Transfer Protocol (HTTP), where each status code carries a unique identifier. The "4xx" series is specifically reserved for client-side errors, and "404" represents the specific error encountered when a requested resource is not found.
To enhance user experience and mitigate the frustration associated with 404 errors, websites often provide customized 404 error pages. These pages may include search bars, suggested links, or other suggestions to help users navigate through the site effectively.
Overall, 404 is a website error status code that relays to users that the requested web resource cannot be found, acting as a communication tool between clients and servers.
The term "404" originated from the field of computer programming and specifically relates to the HTTP error code 404 Not Found. It did not have an etymology in the traditional sense, as it is simply a numerical designation assigned to a specific error in the HTTP protocol.
The HTTP error codes were established by the Internet Engineering Task Force (IETF) to provide a standardized way to indicate various types of server-client communication issues. The number "404" was chosen to represent the error that occurs when a client sends a request for a resource or webpage that the server cannot find.
The 404 error code was included in the HTTP specification in 1992, and it became widely recognized as the standard response when encountering a missing or non-existent webpage. Over time, "404" gained popularity and entered common usage as a descriptive term for a web page or resource that cannot be found.