Infrastructure as a Service (IaaS): is one of the ‘layers’ in the Cloud Computing model; the three fundamental service models being:

Infrastructure as a Service (IaaS): hardware is provided by an external provider and managed for you

Platform as a Service (PaaS): in addition to hardware, your operating system layer is managed for you

Software as a Service (SaaS): further to the above, an application layer is provided and managed for you – you won’t see or have to worry about the first two layers

How it Works

As with all cloud computing services, it provides access to computing resource in a virtualised environment, “the Cloud”, across a public connection, usually the internet. With IaaS, however, the client is given access to virtualised components in order to build their own IT platforms.

The computing resource provided is specifically that of virtualised hardware, in other words, computing infrastructure. The definition includes such offerings as virtual server space, network connections, bandwidth, IP addresses and load balancers.

Physically, the pool of hardware resource is pulled from a multitude of servers and networks usually distributed across numerous data centres, all of which the cloud provider is responsible for maintaining.

Examples of IaaS

Utilising pooled server and networking resources in which a business can store data and run applications. Expanding businesses can scale their infrastructure in accordance with growth

Hosting of websites on virtual servers which are founded upon pooled resources from underlying physical servers

A virtualised network of interconnected virtual servers which can be used to offer enhanced cloud hosting capabilities, enterprise IT infrastructure or to integrate operations



IaaS can offer many benefits to enterprise customers to create cost effective and easily scalable IT solutions where the complexities and expenses of managing the underlying hardware are outsourced to the cloud provider.

There are particular benefits where the scale of operations fluctuates, or where a business is looking to expand, as they can tap into the cloud resource as and when they need it rather than purchase, install and integrate hardware themselves.

A typical Infrastructure as a Service offering can deliver the following features and benefits:

Scalability; resource is available as and when you it, therefore there are no delays in expanding capacity or any wastage of unused capability

No hardware CAPEX; the underlying physical hardware supporting IaaS is set up and maintained by a cloud provider, saving you time and cost

Utility style costing; the service can be accessed on demand and you only pay for the resource that you actually use

Location independence; the service can be accessed from anywhere using the internet, so long as the security protocol of the cloud lets it

Physical security of data center location; services available through a public cloud, or private clouds hosted externally with the cloud provider

No single point of failure; the multitude of hardware resources means that should one aspect of the service fail the service will be unaffected