Cloud computing service models || Iaas, Paas and Saas || Ms Azure
IaaS lets you rent IT infrastructure - servers and virtual machines, storage, networks and operating systems - from a cloud provider on a pay-as-you-go basis.
PaaS is designed to give users access to the components they require to quickly develop and operate web or mobile applications over the Internet, without worrying about setting up or managing the underlying infrastructure of servers, storage, networks and databases.
SaaS is a method for delivering software applications over the Internet where cloud providers host and manage the software applications making it easier to have the same application on all of your devices at once by accessing it in the cloud.