What Is A DNS Server and What Does It Do?

Now that you have decided to take your business online, registered for a domain name and started working on building an online presence, there are some basic things you should know about. One of these is DNS or the Domain Name System. 

It is an important part of how the internet works. It is that part of the internet that translates human-friendly names into machine-readable addresses. A DNS Server is the main component of the system that implements the DNS protocol and manages, processes and maintains the internet domain names. 

In this post, we try to understand DNS Server and its purpose in detail.

What is a DNS Server?

Designed to find and deliver websites requested by users over the private network or the internet, a DNS server is a computer on the internet that hosts a service accessible across the internet. It runs specialized software and is constantly connected to the network. 

A DNS Server is meant to store a database of network names, domain names, DNS records, internet hosts and other related information. The most important function of a DNS server is to translate the domain name into the respective IP address. When it receives a query for domain name resolution, DNS records are searched and the record found is returned. If the record is not found, the query is passed to other DNS servers until it is found.

The DNS is a distributed system in a hierarchy consisting of several DNS servers. Any computer registered to join the DNS is called a DNS Server. Whenever you enter a domain name into the web browser, the browser requests the DNS Server for the IP address for the domain and the server tries to return it. 

The Purpose of DNS Servers

It is easier for human beings to remember hostname like google.com than to remember the web site's IP address such as 173.194.32.195. When you want to open the website of Google, you just need to type http://www.google.com. However, computers and network devices find it hard to work with domain names when locating one another on the internet. Using IP addresses is more efficient and easier for them. 

Without a DNS Server, users would have to manually remember and enter the IP addresses for the website they want to visit. As the DNS takes care of the IP address details, you just need to remember the domain name. If the website’s IP address changes due to some reason, the DNS will manage the job of mapping the new IP address to the domain name and you don’t have to worry about anything. 

DNS System

The Domain Name Server System usually consists of DNS servers that work together to provide resolution to IP address mapping for registered systems on the internet. The root (main) DNS servers are owned and managed by several organizations and located mainly in the United States. 

Other companies like ISP have their DNS servers linked to the root servers in a hierarchical organization to provide a distributed system. You need not manage a DNS server or create DNS records to be able to use the internet. However, it is necessary to access the DNS server which is usually through the IP address provided to you by your internet service provider. Most systems are configured to obtain the DNS server IP address automatically. 

DNS Root Servers

DNS root servers are located at the top of the DNS system. There are 13 DNS root servers on the planet which store the complete database of all the domain names and their associated IP addresses. So a DNS request would eventually reach the DNS root server if no other server has the matching IP address. These DNS servers are named using the first 13 letters of the alphabet from A through M. Ten of these 13 servers are in the US, one in Japan, one in Stockholm and one in London. 

Primary and Secondary DNS Servers

Most of the time, when you get connected to the internet service provider, a primary and a secondary DNS server is configured on the computer or router. There are two DNS servers so that if one of them fails, the other can be used to resolve the domain names you enter.