E-commerce refers to the buying and selling of goods and services online. The document discusses the major categories of e-commerce including business-to-business, consumer-to-consumer, and consumer-to-business. It also outlines the basic components required for a successful e-commerce model including consumers, businesses, content, and community. Finally, it discusses some of the technical components behind e-commerce websites like web servers, databases, and payment processing as well as both the current growth of e-commerce in India and its future potential.