What is IaaS? Infrastructure-as-a-service explained
Cloud computing isn’t one monolithic type of offering, but an assortment of services aimed at meeting the various IT needs of an organization.
One such service provided via the cloud is infrastructure-as-a-service (IaaS), which delivers virtualized computing resources to organizations typically via the internet. IaaS is one of main types of cloud services, along with 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.
Organizations that use IaaS can self-provision the infrastructure services and pay for them on a per-use basis. Fees are typically paid by the hour, week, or month, depending on the service contract. In some cases, providers charge clients for infrastructure services based on the amount of virtual machine (VM) capacity they’re using over a period of time.
IaaS vs. PaaS vs. SaaS
Similar to other cloud computing services, IaaS provides access to IT resources in a virtualized environment, across a public connection that’s typically the internet. But with IaaS, you are provided access to virtualized components so that you can create your own IT platforms on it—rather than in your own data center.
IaaS is not to be confused with PaaS, a cloud-based offering in which service providers deliver platforms to clients that allow them to develop, run, and manage business applications without the need to build and maintain the infrastructure such software development processes typically require.
IaaS also differs from SaaS, a software distribution model in which a service provider hosts applications for customers and makes them available to these customers via the internet.
The pool of IaaS services offered to clients is pulled from multiple servers and networks that are generally distributed across numerous data centers that are owned, operated, and maintained by cloud providers.
IaaS resources can be either single-tenant or multitenant, and they are hosted in the service provider’s data center.
“Multitenant” means multiple clients share those resources, even though their systems are kept separate. This is the most common way to deliver IaaS because it is both highly efficient and scalable, allowing cloud computing’s generally lower costs.
By contrast, single-tenant systems exist to serve clients who need strict separation from others, but at a higher cost. Single-tenant systems are more like traditional hosting services where a third-party provider essentially rents you dedicated space in its data center, but a true single-tenant IaaS also offers cloud-specific capabilities such as scalability and access to a wide range of platform technologies that hosting services often cannot provide.
You can create your own internal IaaS in your own data center using cloud computing technologies, but this is not true IaaS. It’s really a traditional data center that uses modern, cloud-style technologies. A cloud-based IaaS provider typically offers greater scalability, greater selection of technology options, on-demand availability, and usually much better security because it has created its IaaS platform to support hundreds or thousands of customers.
