Cloud services can be availed in different modes – IaaS, PaaS, and SaaS are the common ones. In IaaS, you pay per use for services availed, such as storage, network, virtualization, etc. In PaaS, you avail both hardware as well as software offered by Cloud. In SaaS, you avail third-party software and services over the Cloud. Businesses can choose their preference for IaaS, PaaS, or SaaS as per business requirements.