Infrastructure as a Service (IaaS) is a form of cloud computing that provides virtualized computing resources over the internet. IaaS is one of the three main categories of cloud computing services, alongside software as a service (SaaS) and platform as a service (PaaS). In the IaaS model, third-party service providers host hardware equipment, operating systems and other software, servers, storage systems and various other IT components for customers in a highly automated delivery model. In some cases, IaaS providers also handle tasks such as ongoing systems maintenance, data backup and business continuity.

In an IaaS model, a cloud provider hosts the infrastructure components traditionally present in an on-premise data center including servers, storage and networking hardware, as well as the virtualization or hypervisor layer. The IaaS provider also supplies a range of services to accompany those infrastructure components. These can include detailed billing, monitoring, log access, security, load balancing and clustering, as well as storage resiliency such as backup, replication and recovery. These services are increasingly policy-driven, enabling IaaS users to implement greater levels of automation and orchestration for important infrastructure tasks.

IaaS customers access resources and services through a wide area network (WAN) such as the internet and can use the cloud provider’s services to install the remaining elements of an application stack. For example, the user can log in to the IaaS platform to create virtual machines. Customers can then use the provider’s services to track costs, monitor performance, balance network traffic, troubleshoot application issues, manage disaster recovery and more.

Any cloud computing model requires the participation of a provider. The provider is often a third-party organization that specializes in selling IaaS. IaaS provides the users with many advantages:

• Scalability: One of the main benefits of IaaS is the scalability it offers. Through a subscription service, you access the IT system you require when you need it. Due to its virtualization, scaling up your systems can be done quickly and efficiently, minimizing downtime.
• Minimized hardware maintenance: The hardware behind your IaaS system is managed externally, minimizing the time and money your business spends on this type of maintenance.
• Flexibility: Many IaaS systems can be accessed remotely, although this will vary from system to system.
• Reduced downtime: If your hardware fails, you will usually need to wait for a repair, impacting the productivity of both your staff and business overall.

On demand access: An IaaS system can be accessed on demand and you will only pay for the resources you use, keeping costs down.