The popular notion of e-commerce is a consumer interacting with a Web page to buy a book from Amazon or a ticket from Expedia. This is an important aspect of e-commerce, but the applications and technologies used in e-commerce are much wider than business-to-consumer e-commerce facilitated by the Internet and the World Wide Web. E-commerce is summarized by the phrase “doing business electronically,” and to that we should add the qualification that the business is conducted between the organization and some external party. E-commerce is defined by Wigland (1997, p. 5) as “…the seamless application of information and communications technology from its point of origin to its endpoint along the entire value chain of business processes conducted electronically and designed to enable the accomplishment of business goals.” This includes business-to-business transactions as well as business-to-consumer transactions, and does not presume the type of technology that is used to facilitate these transactions. There are authors that seek to define e-commerce in a way that limits the term to business transacted over the Internet, but this seems to be without merit: Did not transactions conducted using Minitel or Prodigy serve the same purpose as today’s Web-based transactions, and does not the development of m-commerce still come within the more general classifications of e-commerce and e-business? Whiteley (2000) suggests that e-commerce was facilitated by three technologies: electronic data interchange (EDI), electronic markets, and the Internet- (or e-shop) type facilities. EDI and electronic markets predate the e-shop model and, for the Encyclopedia of E-Commerce, E-Government, and Mobile Commerce, this article will concentrate on EDI.