A Domain Name System (DNS) server is a computer which contains a list of domain names along with their associated IP addresses. Whenever you key in the URL in your internet browser, your computer will consult a DNS server to lookup the IP address for the domain name inside your URL.
How does it work
When you want to access the Google search website, you will key in www.google.com into your browser. Your computer will then check with the DNS server what is the IP address for google.com which is the domain name in the URL. Once the IP address is returned by the DNS server, your browser can then make a network connection to that IP address to retrieve the webpage content.
Computers talk to each other via IP addresses on the Internet and not using the domain names. Therefore, DNS servers serve a vital role in operating a sort of phone book to lookup public websites’ IP addresses so that the end users can read the contents of those websites.
While some websites can be accessed using their IP addresses, it is a lot easier for a human to memorize words instead of numbers, hence the use of the domain names. Another advantage of using domain names and a DNS server is that some websites may have multiple IP addresses as they may operate multiple web servers as part of a load balancing strategy to serve more users concurrently. You don’t have to memorize those IP addresses but just remember the single domain name for that website. You’ll be automatically served by one of those IP addresses.
How do you get a DNS server
Internet Service Providers (ISP) will usually automatically configure their users network connections via Dynamic Host Configuration Protocol (DHCP) to assign 2 DNS servers for the users’ use when browsing the Internet. These are the primary and secondary DNS servers. All attempts to resolve a domain name to its IP address will usually be tried with the primary DNS server first, failing which it will then try the secondary.
There are also free DNS servers out there for the general public to use if they feel that the DNS servers being assigned by their ISPs are too slow or are blocking certain websites.
Some of the free DNS servers available: