DNS Servers connect your domain to your hosting services. You can use Nominus servers for free or update to external servers if you prefer.
You can think of the Domain Name System (DNS) as the phonebook of the Internet. When users type domains such as ‘bing.com’ or ‘google.com’ into their browsers, the DNS is in charge of finding the correct IP address for those sites. Browsers then use those IP addresses to communicate directly with the server of origin to display website information. All of this happens because of the DNS servers: they are machines dedicated to answering DNS queries.