E-commerce involves digital transactions between organizations and individuals. Unique features include ubiquity, global reach, customization, and social networking. Digital markets have reduced costs and more transparency. Digital goods can be delivered over networks at low cost. There are three main types of e-commerce: business-to-consumer, business-to-business, and consumer-to-consumer. Principal models include retailers, brokers, market creators, and content providers generating revenue from advertising, sales, subscriptions, and transactions. Building successful e-commerce requires understanding objectives and selecting appropriate technology.