Payment systems and marketing are often specific to ecommerce types, so make sure you have an integrated picture before deciding your Ecommerce business. Ecommerce Definition: ecommerce, e-commerce, or electronic commerce is defined as the conduct of a financial transactions by electronic means. With the growth of commerce on the Internet and the Web, ecommerce often refers to purchases from online stores on the Web, otherwise knows as e-commerce Web sites. They may also be referred to as "virtual-stores" or Cyber stores. Since the transaction goes through the Internet and the Web, some have suggested another term: I-commerce (Internet commerce), or icommerce. e-commerce can be business to business (B to B) or business to consumer (B to C).