E-commerce, also known as electronic commerce, is the buying and selling of goods or services over the internet. It involves the transfer of information between two or more parties, typically through a website or app. Examples of e-commerce include online shopping, online banking, online stock trading, and online auctions. In JavaScript, e-commerce websites can be created by using frameworks such as React and Angular to create user interfaces and Node.js for server-side scripting. Additionally, libraries like Stripe can be used to handle payment processing.