Cloud computing involves delivering hosted services like infrastructure as a service (IaaS), platform as a service (PaaS), and software as a service (SaaS) over the internet. IaaS provides access to computer infrastructure and resources via the web. PaaS delivers a computing platform over the web, providing tools for developers. SaaS delivers applications over the internet rather than installing software locally. Major providers of these cloud services include Amazon, Google, and Salesforce.