E-commerce refers to commercial transactions conducted over the Internet. It began in the 1960s but expanded in the 1990s with companies like eBay and Amazon. There are three main types: business to business (B2B), business to consumer (B2C), and consumer to consumer (C2C). E-commerce provides benefits like convenience, global reach, and 24/7 access to information. While it impacts traditional retailers, it also creates new opportunities for online sales.