E-commerce is short for "electronic commerce" and refers to websites where products or services are directly bought or sold, including both physical and virtual products and services. The exchange of financial data is also an important component of e-commerce in the context of online payments. Email and cell phones are also often associated with e-commerce.

Electronic commerce is enabled by electronic funds transfer, online transaction processing, electronic data interchange, automated data collection systems, inventory management systems, supply chain management, and Internet marketing. Today, most business units are involved in e-commerce, at least to some degree.

Some e-commerce professionals exist only through the Internet, with an e-commerce site and perhaps other sites, but no storefront or physical location. There are also more traditional retail units, with storefronts or physical sites, that also have an Internet presence and include an e-commerce site, either for direct sales or to attract more customers to the physical storefronts.

E-commerce transactions are usually business-to-business or business-to-consumer. There are many common applications of e-commerce. These include supply chain and document logistics automation, enterprise content management, group or bulk purchasing, domestic and international payment systems, instant messaging, newsgroups, and automated online assistants.