When you want to visit a certain website, your web browser looks for a domain name and the router sends a request to the DNS server. If the domain name has been registered, the system sends the corresponding IP address. In this way, the download process goes smoothly.
This process is controlled by the DNS configuration and in most cases goes smoothly. However, sometimes the system fails, gets damaged, or stops working for various reasons. When this happens, the DNS server fails to establish the necessary connection and you get an error message like this: