What are Computer Networks and IP addresses?

Computer network is a group of computers or nodes that are linked to each other to share information and resources. Whereas, IP addresses are generally represented by a 32-bit unsigned binary value. It is represented in a dotted decimal format.

For example, is a valid IP address.

The IP address consists of a pair of numbers −

IP address = <network number><host number>

Let see the pictorial representation of two hosts that are communicated with the help of Network and IP address.


Step 1 − The service that is used to convert the Domain name to IP address is called Domain Name Service.

Step 2 − The port number is used to Identify a particular host, for well known services the port numbers are predefined and fixed.

For example −

http=>port number=80
ftp=> port number=21
SMTP=> Port number=25

Step 3 − Even though our intention is to reach google.com, we have to visit DNS first and then getting the IP address of google.com we will get the google home page. Actually this is overhead, also called DNS overhead.

This problem can be rectified when we get the IP address of google.com. For the first time, we need to store that in our personal system for some time. Later on, when we try to access the site again we can get the IP address directly from our system.

By doing this there is no need to get DNS for every time access which reduces the overheads. If the IP address expires then there is no other alternative we have to go to DNS.

IP addresses are used by the IP protocol helpful to identify a host on the Internet. Generally, speaking, an IP address identifies an interface that is capable of sending and receiving IP datagrams.