This document provides an introduction to cloud computing. It explains that cloud computing represents a major shift in computing similar to the transition from mainframes to personal computers. With cloud computing, computing power and data storage are provided as an abstract service via the internet rather than requiring individuals and businesses to maintain their own computing infrastructure. This allows users to access powerful applications and services at low costs without the hassle of maintenance. The document argues that cloud computing will impact a wide range of users from individuals to businesses to governments and enable new opportunities for entrepreneurship.