The error 404 message indicates that the webpage you are trying to access cannot be found. This commonly occurs when a URL is mistyped or when a page has been removed or moved. When encountering a 404 error, users are typically redirected to a standard error page, prompting them to check the URL or navigate back to the website's homepage. It is important for website administrators to monitor and fix 404 errors to provide a better user experience and ensure that visitors can easily access the content they are looking for.