E-commerce, short for electronic commerce, refers to the buying and selling of goods and services over the internet. It involves online transactions between businesses and consumers, as well as transactions between businesses. E-commerce has become increasingly popular due to the convenience it offers, allowing people to shop and conduct business activities from the comfort of their homes or any location with internet access.

Key components of e-commerce include online shopping websites, electronic payments, online banking, and various other online services. E-commerce can take various forms, such as business-to-consumer (B2C), business-to-business (B2B), consumer-to-consumer (C2C), and mobile commerce (m-commerce). Here's a brief explanation of each:

1. B2C (Business-to-Consumer): In B2C e-commerce, businesses sell products or services directly to individual consumers. Examples include online retail stores, travel websites, and digital content providers.
2. B2B (Business-to-Business): B2B e-commerce involves transactions between businesses. This can include the exchange of goods, services, or information between companies. Examples include wholesale marketplaces and online platforms for business procurement.
3. C2C (Consumer-to-Consumer): C2C e-commerce facilitates transactions between individual consumers. Online auction platforms and classified advertisements are common examples where individuals can buy and sell products or services to each other.
4. M-Commerce (Mobile Commerce): M-commerce refers to e-commerce transactions conducted using mobile devices, such as smartphones or tablets. Mobile apps and mobile-optimized websites enable users to shop and make transactions on the go.

E-commerce has significantly transformed the way businesses operate and consumers shop, providing a global marketplace that is accessible 24/7. It has also led to the development of various supporting technologies, including secure online payment systems, digital marketing strategies, and advanced logistics and delivery services.