I was discussing with a client the need for customized 404 error pages.
The Error 404 “Page not found” is what is displayed when you visit a page on a website and that page, for whatever, does not exist or is unreachable. Without a valid website to display, the server sends a response to your browser that says “404 Page not found”.
The 404 error is an HTTP (Hypertext Transfer Protocol) regular code. The error response usually will indicate that though your browser was able to communicate with the server, it didn’t find what was requested or there was an error when processing the response.
It’s necessary for your website to be setup to display a standard 404 Error page when necessary. Doing so is not only valuable to visitors, who could be given a list of pages or other resources on your site to choose from instead of seeing just an error page, but also having a customized 404 error page is beneficial for SEO. So, if you don’t already have a 404 Error page please make sure your web developer sets one up for you immediately.