A cloud service model that delivers a virtualized computing environment as a service over the internet by the provider, allowing companies to subscribe to computing infrastructure resources.
IaaS includes hosting services on virtual machines, networks, storage, load balancers, firewalls and other resources that allow you to take advantage of such cloud benefits as scalability and global access. With IaaS, customers don’t control or manage the infrastructure; they just rent it. Amazon AWS, Microsoft Azure, Google Compute Engine and Rackspace Cloud are examples of IaaS.