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Electronic commerce (e-commerce) has come to be associated with the buying and selling of goods on the Internet or, more specifically, the Web because it takes advantage of Web protocols. It involves customer-oriented processes like those used at online shopping malls, including the presentation of online catalogs, shopping cart schemes, and payment authorization schemes. This customer-oriented e-commerce is often called B2C (business to consumer).

Electronic commerce also includes business-to-business (B2B) transactions, such as automatic inventory reordering and the exchange of electronic documents (purchase orders, invoices, and soon). B2B is usually built upon VPN-based extranets. A VPN is a private connection across the Internet or some other network, secured by an encrypting tunneling protocol such as IPSec (IP Security). B2B may integrate EDI (Electronic Data Interchange), an older technique of exchanging electronic business documents, in order to access legacy system and data. EDI has now been integrated into newer Web protocols. See "EDI (Electronic Data Interchange)" for more information.