The .htaccess file is what Apache web servers use to allow you to fine-tune your web server configurations at a directory level. Other types of web servers handle the customization of 404 error pages differently. (A web server, in this context, is the software that runs on your web host's computer.

A custom 404 page lets you provide a user-friendly website to your visitors even in the midst of an error. Very few users, when presented with a 404, will do more beyond click back to get out of the mistake. A custom 404 page is a good opportunity to keep them on your site and do more to redirect them to their destination.

It is important to have customized 404 pages with recommended navigational options when website visitors request pages that return a 404 response code.

A 404 page is what a user sees after they attempt to reach a non-existent page on your website (because they've clicked on a broken link, the page has been deleted, or they've mistyped a URL).