When DNS was not into existence, one had to download a Host file containing host names and their corresponding IP address. But with increase in number of hosts of internet, the size of host file also increased. This resulted in increased traffic on downloading this file. To solve this problem the DNS system was introduced. 

Domain Name System:-

helps to resolve the host name to an address. It uses a hierarchical naming scheme and distributed database of IP addresses and associated names 

IP Address:-

IP address is a unique logical address assigned to a machine over the network. An IP address exhibits the following properties: IP address is the unique address assigned to each host present on Internet. IP address is 32 bits 4bytes long. IP address consists of two components: network component and host component. Each of the 4 bytes is represented by a number from 0 to 255, separated with dots. For example 

Domain Name System Architecture:-

The Domain name system comprises of Domain Names, Domain Name Space, Name Server that have been described below: 

Domain Names:-

Domain Name is a symbolic string associated with an IP address. There are several domain names available; some of them are generic such as com, edu, gov, net etc, while some country level domain names such as au, in, za, us etc