Domain Name System is a system or concept used to name hosts connected to the network. DNS is hierarchical which means there is a tree-like connection in the domain names. DNS is invented by Paul Mockapetris in 1983.
What is Domain Name
A domain name identifies hosts connected to the network. Domain names are unique. For example, www.poftut.com is a domain name.
- Here com is top-level domain which is administrated by global organization a.k.a ICAN and its low-level partners.
- poftut is bought by me from a domain name reseller and registered in the whole world internet system to me.
- www is a real hostname which is my webserver name and administrated by me.
Now the real question of how to get the IP address of www.poftut.com to access the webserver. The solution is name server. There are global DNS servers that provide information about the queried domain name and redirects to the related sub-level DNS server. Low-level DNS server is all ready knows the IP and hostnames about poftut.com because I have configured them. So the IP address is sent back as an answer to the asking user. The critical operation to translate a domain name to the IP is done by more than one DNS servers by asking each other is a hierarchical manner.
DNS Server Client Configuration
Clients need at least one DNS server to resolve internet domain names which is generally modem IP address or ISP DNS IP addresses for the most of the home users.