E-Commerce Business-to-Business (B2B). E-Commerce category involves e-business center and direct market relationships between firms. For example, many companies offer secure Web site contains a catalog of e-commerce via the Internet or extranets for customers of the company's suppliers and fig. It is also very important is the portal of B2B e-Commerce marketplace that provides auctions and buy jaul for various companies. Other companies can rely on Electronic Data Interchange-EDI, via the Internet or extranets to exchange computer-to-computer over a wide range of e-commerce documents with large customers of the company and its suppliers.