Short for
Infrastructure as a Service, IaaS is defined as computer
infrastructure, such as
virtualization,
being delivered as a service. IaaS is popular in the data center where software
and servers are purchased as a fully
outsourced
service and usually billed on usage and how much of the resource is
used — compared to the traditional method of buying software and servers outright.
May also be called
enterprise-level hosting platform.
Sun Microsystems identifies Infrastructure as a Service (IaaS) as one of three layers of
cloud computing, in addition to Software as a
Service (SaaS) and Platform as a Service (PaaS).