Infrastructure as a Service is a provision model in which an organization outsources the equipment used to support operations, including storage, hardware, servers and networking components. The service provider owns the equipment and is responsible for housing, running and maintaining it. The client typically pays on a per-use basis.
It include:

1. Hardware management.
2. Physical space management.
3. Utility computing service and billing model.
4. Automation of administrative tasks.
5. Dynamic scaling.
6. Desktop virtualization.
7. Policy-based services.
8. Internet connectivity.

Scalability : resource is available as and when the client needs it and, therefore, there are no delays in expanding capacity or the wastage of unused capacity.
No investment in hardware : the underlying physical hardware that supports an IaaS service is set up and maintained by the cloud provider, saving the time and cost of doing so on the client side.
Utility style costing : the service can be accessed on demand and the client only pays for the resource that they actually use.
Location independence : the service can usually be accessed from any location as long as there is an internet connection and the security protocol of the cloud allows it.
Physical security of data centre locations : services available through a public cloud, or private clouds hosted externally with the cloud provider, benefit from the physical security afforded to the servers which are hosted within a data centre.
No single point of failure : if one server or network switch, for example, were to fail, the broader service would be unaffected due to the remaining multitude of hardware resources and redundancy configurations. For many services if one entire data center were to go offline, nevermind one server, the IaaS service could still run successfully.

Infrastructure Management