Infrastructure as a Service

Infrastructure as a Service (IaaS) is the delivery of computer infrastructure (typically a platform virtualization environment) as a service.

Key components

Implementations typically include the following layered components:

Service level agreements (optional)
Utility computing billing (eg per instance hour)
Platform virtualization environment for running client specified virtual machines
Computer hardware (typically set up as a grid for massive horizontal scalability)
Computer network (including firewalls, load balancing, etc.)
Internet connectivity