This document provides an overview of e-commerce. It defines e-commerce as buying and selling of products or services over electronic systems like the internet. The history of e-commerce is traced back to the growth of credit cards and ATMs in the 1980s. The document outlines the main advantages as faster transactions, lower costs, and 24/7 availability, and disadvantages as lack of quality guarantees and need for internet access. It describes the main types of e-commerce as business-to-business, business-to-consumer, consumer-to-business, and consumer-to-consumer and provides examples of each. Finally, it thanks the audience without specifying any examples of e-commerce websites.