E-commerce, short for electronic commerce, refers to the buying and selling of goods and services over the internet. It involves online transactions, digital communication, and electronic data exchange between businesses, individuals, or organizations. E-commerce has revolutionized the way businesses operate and has provided consumers with a convenient and efficient way to shop.

There are several types of e-commerce:

1. Business-to-Consumer (B2C): This is the most common type of e-commerce, where businesses sell products or services directly to consumers. Examples include online retail giants like Amazon and eBay, where individuals can purchase a wide range of products from various sellers.

2. Business-to-Business (B2B): In B2B e-commerce, businesses sell products or services to other businesses. This type of e-commerce often involves bulk orders, wholesale pricing, and long-term contracts. An example is Alibaba, a platform connecting manufacturers and wholesalers worldwide.

3. Consumer-to-Consumer (C2C): C2C e-commerce involves individuals selling products or services directly to other individuals. Online marketplaces like Craigslist and Facebook Marketplace enable users to buy and sell used items, rent accommodations, or offer services to each other.

4. Consumer-to-Business (C2B): C2B e-commerce occurs when individuals sell their products or services to businesses. For instance, freelance platforms such as Upwork and Fiverr allow individuals to offer their skills and services to companies looking for specific expertise.

5. Mobile Commerce (m-commerce): M-commerce refers to e-commerce transactions conducted through mobile devices like smartphones and tablets. With the increasing popularity of mobile apps and mobile-friendly websites, consumers can shop, make payments, and conduct transactions on the go. Examples include mobile banking apps, food delivery apps like Uber Eats, and retail apps like Amazon's mobile app.

E-commerce offers numerous advantages, including convenience, global reach, cost savings, and personalized shopping experiences. It allows businesses to operate 24/7 without physical store limitations, reach a wider customer base, reduce overhead costs, and provide personalized recommendations based on customer preferences.

References:
- Laudon, K. C., & Traver, C. G. (2020). E-commerce: Business, technology, society. Pearson.
- Chaffey, D., & Ellis-Chadwick, F. (2019). Digital marketing: Strategy, implementation and practice. Pearson.