Whenever a page on your website doesn't load, an error message will be shown to the visitor. Since there are different errors, there are different pages that will appear, but what is typical for all of them is that they're generic and almost certainly will have absolutely nothing that is similar to the layout of your site, which could be irritating for any website visitor. That is the reason why website hosting service providers have introduced a function called Custom Error Pages. For a variety of different errors, site visitors shall see your unique content, which may be informative or humorous, based on your personal preference, and that will match the overall style and design of your Internet site, so the pages won't seem like they aren't part of your Internet site at all. You may use this option for a number of errors - 400 (Bad request), 401 (Unauthorized), 403 (Forbidden) and 404 (File not Found).