YouTip

## 404 NOT FOUND! Sorry, the article you requested was not found!! The 404 page is an essential page for any website, as it carries the responsibility of user experience and SEO optimization. A 404 page usually appears when a user visits a page that does not exist or has been deleted on the website, and the server returns a 404 error. If the webmaster does not set up a 404 page, dead links will occur. When search engine spiders crawl such URLs, it is not conducive to search engine indexing. ## Origin of 404 Not Found It is said that before the third technological revolution, the Internet existed in the form of a large central database, which was located in room 404. At that time, all requests were handled manually. If the requested file was not found in the database, or if the requester wrote the wrong file number, the user would receive a return message: room 404 : file not found. Later