Cloud computing is the practice of using remote servers on the Internet to store, manage, and process data rather than local servers or personal devices. It provides scalability, allowing resources to expand or contract as needed. There are several types of cloud including public, private, community, and hybrid clouds. Cloud services also come in various models like Software as a Service (SaaS), Platform as a Service (PaaS), and Infrastructure as a Service (IaaS). While cloud computing provides advantages like disaster recovery and reduced costs, it also faces challenges regarding downtime, security, and data transfer expenses.