What's the point of a 404 page? [duplicate]

1. What is the reason of displaying a 404 pages?
2. What is the purpose of a 404 error?
3. Why are custom 404 pages a good idea?
4. What does it mean and why the number 404 is there a better way of letting users know when a link to a website is not working?

What is the reason of displaying a 404 pages?

404 error codes are generated when a user attempts to access a webpage that does not exist, has been moved, or has a dead or broken link. The 404 error code is one of the most frequent errors a web user encounters. Servers are required to respond to client requests, such as when a user attempts to visit a webpage.

What is the purpose of a 404 error?

The HTTP 404 Not Found response status code indicates that the server cannot find the requested resource. Links that lead to a 404 page are often called broken or dead links and can be subject to link rot. A 404 status code only indicates that the resource is missing: not whether the absence is temporary or permanent.

Why are custom 404 pages a good idea?

If users reach a dead end on a default error page, they will leave the website and search for something else. But with a custom 404 error page, you can give users a clear path to a new destination on your website, keeping them on your site.

What does it mean and why the number 404 is there a better way of letting users know when a link to a website is not working?

A 404 error means that the page can't be found. Usually, this happens when the URL or its content was deleted or moved. 404 errors are bad for the user experience and bad for SEO — Google will classify your site as unreliable if it sees that a page that had previously existed is no longer available.