A 404 or Not Found page should occur to a user if they enter a non-existent URL, or if the server cannot display the requested page for some reason. The absence of a 404 page can cause the visitor to leave the site, which has a negative effect on the behavioral component that the search engine evaluates. In addition, if it is an existing page that is currently unavailable, the absence of a 404 page can cause the search engine to stop indexing the page and you will lose position on it, which will also hurt the entire site.


