In this cloud service, all infrastructure components such as the servers, computing power, network capacity, communication devices, storage, archiving and backup systems, and other components of the data center architecture and network infrastructure are provided to the user by a cloud service provider. Users can access these virtual services via broadband networks and are charged according to actual usage.
IaaS offerings include the computing hardware, the network with its firewalls and routers, user-specific virtualized platforms and the quality of service agreements( SLA). In addition to the cost benefits, users have the advantages of working with pre-packaged environments and always with the latest technology and secure platforms; they don't have to worry about upgrades, operations and maintenance; they can better absorb peak loads; and they can scaleto meet demand. However, users need to know the cloud infrastructure. This includes knowledge of the entire stack including installation, configuration, maintenance and operation of the entire virtual infrastructure.
Infrastructure-as-a-Service offers are available from many well-known software and hardware providers, including IBM, Hewlett Packard, Microsoft, Sun.