If you've ever used the Internet, it's a good bet that you've used the Domain Name System, or DNS, even without realizing it. DNS is a protocol within the set of standards for how computers exchange data on the Internet and on many private networks, known as the TCP/IP protocol suite. Its basic job is to turn a user-friendly domain name like "google.com" into an Internet Protocol (IP) address like 22.214.171.124 that computers use to identify each other on the network. It's like your computer's GPS for the Internet.
Computers and other network devices on the Internet use an IP address to route your request to the site you entered in URl box of your browser. This is similar to dialing a phone number to connect to the person you're trying to call. Thanks to DNS, though, you don't have to keep your own address book of IP addresses. Instead, you just connect through a domain name server, also called a DNS server or name server, which manages a massive database that maps domain names to IP addresses.
To keep it simple
- Domain names are alphanumeric names for IP addresses e.g., www.geekgyan.com, www.google.com.
- The domain name system (DNS) is an Internet-wide distributed database that translates betweem domain names and IP addresses.
What was There before DNS
- Before DNS (until 1985), the name-to-IP address was done by downloading a single file (hosts.txt ) from a central server with FTP.
- Names in hosts.txt are not structured.
- The hosts.txt file still works on most operating systems. It can be used to define local names.
Resolver and name server
- An application program on a host accesses the domain system through a DNS client, called the resolver.
- Resolver contacts DNS server, called name server.
- DNS server returns IP address to resolver which passes the IP address to application.
- Reverse lookups are also possible, i.e., find the hostname given an IP address.
Which DNS server To use
Without DNS servers, the Internet would shut down very quickly. But how does your computer know what DNS server to use? Typically, when you connect to your home network, Internet service provider (ISP) or WiFi network, the modem or router that assigns your computer's network address also sends some important network configuration information to your computer or mobile device. That configuration includes one or more DNS servers that the device should use when translating DNS names to IP address.
There is much more about DNS but above i have tried covering few basics of DNS and it's working. Hope it help's up in clearing some of your doubt's regarding this topic.