Infrastructure-as-a-service (IaaS) refers to servers and storage that are hosted in the cloud.
What does infrastructure-as-a-service (IaaS) mean?
In computing, infrastructure refers to the computers and servers running code and storing data and the wires and appliances connecting those machines. For example, servers, hard drives, and routers are all part of the infrastructure. Before cloud computing, most businesses hosted their infrastructure and ran all their applications on-premise.
Infrastructure-as-a-service, or IaaS for short, is when a cloud computing vendor hosts the infrastructure on behalf of their customers. The vendor hosts the infrastructure in “the cloud” – in other words, in various data centers. Their customers access this cloud infrastructure over the Internet. They can use it to build and host web applications, store data, run business logic, or do anything else that could be done on traditional on-premise infrastructure, but often with more flexibility.
What are the main models of cloud computing?
The three main service models of cloud computing are:
- Infrastructure-as-a-service (IaaS)
- Platform-as-a-service (PaaS)
- Software-as-a-service (SaaS)
IaaS vs. PaaS vs. SaaS
IaaS is infrastructure hosted in the cloud. IaaS includes virtual servers and cloud storage, cloud security, and access to data center resources (managed by the IaaS provider).
Platform-as-a-service (PaaS) is the next layer in the cloud computing service model. It provides developers with a platform for building applications. Most PaaS offerings include development tools, middleware, operating systems, databases and database management, and infrastructure. A PaaS provider either manages the infrastructure themselves or purchases it as a service from an IaaS provider.
Software-as-a-service (SaaS) is a complete application hosted and managed in the cloud. SaaS users subscribe to an application and access it over the Internet rather than purchasing it once and installing it locally.
Why do developers and businesses use IaaS?
Scalability: Expanding a business with IaaS as the foundation is much easier. Instead of purchasing, installing, and maintaining a new server every time the company needs to scale up, they can add a new server on demand through the IaaS provider. This on-demand scalability is a significant benefit of cloud computing across all cloud service models.
Fewer resources dedicated to server maintenance: With IaaS, a company has outsourced server purchasing, maintenance, and updating to the IaaS provider. This is typically cheaper and requires less time and labor from internal teams than they would need to host their infrastructure.
Faster time to market: Companies using IaaS can deploy and update applications much faster since cloud providers can offer however much infrastructure they need as they need it.
How does IaaS fit into multi-cloud and hybrid-cloud deployments?
Multi-cloud deployments and most hybrid cloud deployments involve integrating multiple cloud services. Many businesses taking a multi-cloud approach use one cloud provider for IaaS and integrate with PaaS and SaaS services. Some companies may also utilize various IaaS providers for redundancy or handling separate computing workloads in parallel.
Businesses using hybrid clouds can integrate IaaS with on-premise infrastructure, private clouds, and other public cloud services.
