Infrastructure as a Service (IaaS): Provides virtualized computing resources over the internet. Examples include Amazon Web Services (AWS) and Microsoft Azure. Platform as a Service (PaaS): Supplies a platform allowing customers to develop, run, and manage applications without the complexity of building and maintaining the underlying infrastructure. Examples include Google App Engine and Heroku. Software as a Service (SaaS): Delivers software applications over the internet on a subscription basis. Examples include Salesforce, Google Workspace, and Microsoft Office 365.