What is an IP address :-

In simple terms, its a number that consists of four numbers, separated by periods, that can be between 0 and 255. This number identifies the device (comptuer) that is connected to the Internet, which is a TCP/IP network. It is like the address of your house, but instead of a house number, street, city, state, zipcode, it looks something like this: 127.0.0.1

Each device on the Internet gets assigned a unique IP Address. No two devices can have the same IP Address just like no two houses on your street have the exact same address.

For what is an IP address:-

When your computer is on the Internet, anything you do requires data to be transmitted and received. For example, when you visit a web site, such as tekchandrahi.blogspot.com, data is transmitted to your computer in order to load the content of the web page. The server where tekchandrahi.blogspot.com is located needs to know where to send the data. When you connect to tekchandrahi.blogspot.com, it receives your IP Address and then knows where to send the data. For example, someone that needs to mail you a letter has to know your address in order to send it to you just like a server needs to know your IP Address to send you data.