1. Infrastructure as a Service (IaaS)
2. Platform as a Service (PaaS)
3. Software as a Service (SaaS)
4. Function as a Service (FaaS)

Infrastructure as a Service (Iaas) is a cloud computing model that provides virtualized computing resources over the internet. It provides scalable and on-demand access to essential IT components such as Virtual Machines (VMs) Storage, and networking resources without the need to invest in hardware.