If a particular page on an Internet site does not load for some reason or if a link is not working, the visitor shall see an error page with some generic message. The page shall have nothing in common with the rest of the website, which may make the visitor leave the website. A solution in such a case is a function offered by some website hosting providers - the ability to set your own custom error pages that will have the same design as your website and which can contain any text or images that you'd like based on the specific error. There are four well-known errors that can take place and they involve these particular so-called HTTP status codes - 400, when your browser sends a bad request to the web server and it cannot be processed; 401, if you are supposed to log in to see some page, but you haven't done so yet; 403, if you don't have an authorization to see a specific page; and 404, in case a link that you have clicked leads to a file which doesn't exist. In all of these scenarios, website visitors shall be able to see your customized content instead of a generic error page.