E-commerce, or electronic commerce, is the buying and selling of goods and services over the internet. It eliminates the need for physical stores, allowing businesses to operate globally and consumers to shop conveniently from anywhere, anytime. There are various e-commerce models, including B2C (Business-to-Consumer), B2B (Business-to-Business), and C2C (Consumer-to-Consumer). Popular platforms like Amazon, eBay, and Shopify facilitate online transactions by providing secure payment gateways and user-friendly interfaces. E-commerce offers advantages such as reduced operational costs, personalized shopping experiences, and scalability. However, it also faces challenges like cybersecurity threats, high competition, and logistics management.