Major objective of this article is to Define and Discuss on E commerce. E commerce or electronic commerce, a subset of e business, would be the purchasing, selling, and exchanging of products and services over computer networks such as the Internet through which deals or terms of purchase are performed electronically. Surprisingly, e commerce is not just on the internet or online. Here briefly explain B2B: Business to Business, B2C: Business to Consumer, C2B: Consumer to Business and C2C: Consumer to Consumer.