Officially: an e-Commerce system is conducting of business communication and transactions over networks and through computers. As most restrictively defined, electronic commerce is the buying and selling of goods and services, and the transfer of funds, through digital communications. However it also includes all inter-company and intra-company functions (such as marketing, finance, manufacturing, selling, and negotiation) that enable commerce and use electronic mail, EDI, file transfer, fax, video conferencing, workflow, or interaction with a remote computer.
Electronic commerce also includes buying and selling over the World-Wide Web and the Internet, electronic funds transfer, smart cards, digital cash and all other ways of doing business over digital networks.