This document defines e-commerce and outlines its history and types. E-commerce involves purchasing and selling goods online and has evolved from early electronic funds transfers and electronic data interchange between companies in the 1970s-1980s to the widespread use of the internet for information publishing and online shopping in the 1990s. The main types of e-commerce are business-to-business, business-to-consumer, consumer-to-consumer, consumer-to-business, and mobile commerce. The document also discusses the top e-commerce players in India and provides advantages and disadvantages of e-commerce.