This document provides an overview of cloud computing. It defines cloud computing as network-based computing that takes place over the Internet, providing hardware, software, and networking services to clients. Key characteristics of cloud computing include on-demand services that are available anywhere and anytime, elastic scaling, and pay-as-you-go pricing. The document discusses different cloud service models including Software as a Service (SaaS), Platform as a Service (PaaS), and Infrastructure as a Service (IaaS). It also covers advantages such as lower costs, improved performance and collaboration, and unlimited storage, as well as disadvantages like reliance on internet connectivity and potential security and data loss issues.