Service models refer to the different ways in which services are delivered to users or customers. The most common service models in the context of cloud computing are Infrastructure as a Service (IaaS), Platform as a Service (PaaS), and Software as a Service (SaaS). Each model offers varying levels of control, flexibility, and management, allowing businesses to choose the best fit for their needs. In the IaaS model, users can rent virtualized computing resources over the internet, while PaaS provides a platform for developers to build and deploy applications without managing the underlying infrastructure. SaaS delivers software applications over the internet, allowing users to access them via a web browser without installation.