Commerce is the exchange of goods and services between entities. E-commerce refers to commerce conducted electronically over computer networks like the internet. It allows businesses and consumers to buy and sell goods and services online. Some benefits of e-commerce include low entry costs, reduced transaction costs, and access to global markets. Common e-commerce models include business-to-business, business-to-consumer, and consumer-to-consumer. While e-commerce provides conveniences, it also faces challenges like the inability to examine products physically and not all customers have internet access.