Domain Name Service or DNS is one of the protocols that comprise the TCP/IP suite. The main purpose is to translate IP addresses; whether IPv4, with 32-bit or IPv6 with a 128-bit addressing scheme. This service requires a DNS server and a DNS client, both of which are background software processes.
It is a distributed and hierarchical system. In its entirety, the domain names and matching IP addresses of every website are contained within the domain namespace. Domain names are what we call Uniform Resource Locator (URL) for example, Facebook. The domain names are used because it would be hard for persons to remember the Internet Protocol address of each and every website that they visit on a daily basis. Facebook.com for example uses many different address blocks and some of which are 18.104.22.168/19, 22.214.171.124/20, 126.96.36.199/22 and 188.8.131.52/20. The previous blocks contain many addresses, too many as a matter of fact for the human mind to remember. DNS provides an easy way by taking the URL that is inputted into the browser’s address bar and then translating it when the DNS client, the PC being used to browse, makes a request to view the website. If the request cannot be handled by the local resolver, it goes up the hierarchy to the name server. It then processes the request through a myriad of servers until it receives an answer to the query for the web resource. Once it locates the resource in a subsequent server, it sends it to the original name server that made the query. That name server sends the received response back to the resolver which sends it back to whichever program made the request, most commonly a web browser, which then displays the particular website that is attached URL that was entered.
Home networks bona fide addresses from the ISP the are contracted to or a third-party provider for example OpenDNS. DNS is frequently utilized by programs that need to convert a domain name to an address. This process is called the forward lookup. The DNS is also used to:
1. Find actual mail servers which deliver email via POP3 or IMAP
2. Converting IP addresses to domain names also known as a reverse lookup
It is also used in conjunction with DHCP to allow inter-connectivity in networks. Without DNS and its configuration, the world wide web and the internet wouldn’t be able to share information as quickly or as easily as it does now.