E-commerce--Electronic commerce is any commercial activity or transaction that takes place by means of connected computers. E-commerce can occur between a computer user and an online vendor through an online information service, the Internet, a bulletin board system or between vendor and customer computers through electronic data interchange.

In the early days, e-commerce was defined simply as the buying and selling of goods and services on the Internet, especially the World Wide Web. In practice, this term and a new term, "e-business," are often used interchangeably.

E-tailing--Online retail selling, or electronic retailing. E-tailing makes use of virtual storefronts or a virtual mall, where products for sale are placed in an e-commerce website. As a place for direct retail shopping, with its 24-hour availability, a global reach, the ability to interact and provide custom information and ordering and multimedia prospects, the Web is rapidly becoming a multibillion dollar source of revenue.

A number of businesses already report considerable success. As early as the middle of 1997, Dell Computers reported orders of a million dollars a day. By early 1999, projected e-commerce revenues for business were in the billions of dollars and the stocks of companies deemed most adept at e-commerce were skyrocketing.

Apart from computer and network products, books (Amazon.com), gardening products (Garden.com), music on compact disks (CDNow) and office supplies (SuppliesOnline) were a few of the better-known e-commerce sites. By 1999, even businesses that have always counted on face-to-face customer interaction were planning e-commerce websites and many businesses were planning how to coordinate in-store and Web store retail approaches. Meanwhile, new businesses based entirely on Web sales are being established daily.

B2B--Business-to-Business buying and selling, large-scale transactions over the Internet. An example would be closing a transaction with a freight forwarder to move physical goods from one place to another using Internet resources--from making the placement to paying for the service.

Many are saying that e-commerce growth will rely heavily on B2B transactions instead of those tailored around B2C (Business-to-Consumer) solutions. Thousands of companies that sell products to other companies have discovered that the Web provides not only a 24-hour-a-day showcase for their products but a quick way to reach the right people in a company for more information. Security includes authenticating business transactors, controlling access to resources such as webpages for registered or selected users, encrypting communications and, in general, ensuring the privacy and effectiveness of transactions. Among the most widely used security technologies are SSL (Secure Socket Layer) and RSA (Rivest Shamir Adleman) encryption. Secure Electronic Transactions (SET) is an emerging industry standard.

B2C--Business-to-Consumer transactions, your typical Internet storefront selling products online, like Amazon.com. This was the first form of e-commerce transaction which was applied on the Internet. Any website selling books, CDs, DVDs, computers, equipment peripherals and other such products are categorized under B2C.

M-commerce--Mobile commerce, or e-commerce using mobile devices such as cellular telephones and personal digital assistants. Technology for wireless data transfer is already here, and many businesses are setting up infrastructure and solutions that would enable mobile users to do transactions while on the go. Examples would be paying for your bills only using a cellular phone that is WAP (wireless application protocol) capable or ordering a pizza from your personal digital assistant.