E-commerce involves the buying and selling of products and services over electronic systems like the internet. There are several forces fueling the growth of e-commerce, including economic forces, marketing/customer interaction, and advancing technology. E-commerce can be categorized into business-to-business, business-to-consumer, business-to-government, consumer-to-consumer, and mobile commerce models. Business-to-business comprises the majority of e-commerce transactions and focuses on supply chain management between organizations.