E-commerce refers to the process of buying and selling goods and services over electronic systems like the internet. It emerged in the early 1990s and has grown rapidly since. Most companies now have an online presence. E-commerce can be business-to-business, business-to-consumer, consumer-to-consumer, consumer-to-business, consumer-to-administration, or business-to-administration. It provides advantages like faster transactions, 24/7 availability, low costs, and easy global access to markets. However, it also presents disadvantages like lack of quality guarantees, technical issues, security risks from hackers, and less customer loyalty.