A 404 Not found error is a webserver’s code for:
"There's nothing here."
The error means that your browser is able to communicate with the server but the resource you were looking for isn't there.
404 errors can occur in a large variety of situations. Here are some questions to consider while troubleshooting:
Generally a web developer will try to avoid 404 errors at all costs since Google doesn't like seeing them but if you find a 404 link on a website you may want to check if the website includes a search function that may allow you to find what you're looking for.