What does the HTTP error 404 "The requested resource is not found" specifically mean in the context of localhost IIS?

When you encounter a 404 error on localhost IIS, it signifies that the web server (IIS) is running correctly and responding to requests, but the specific file or resource requested by the browser does not exist at the specified location within the IIS web server's directory structure. This means the path specified in the URL doesn't match any file or directory configured for your website in IIS.