What is IaaS?
Also known as: Infrastructure as a Service
Infrastructure as a Service (IaaS) is a cloud computing model that provides on-demand access to virtualized compute, storage, and networking resources, which the customer configures and manages from the operating system upward.
Infrastructure as a Service (IaaS) is one of the three fundamental cloud service models, alongside Platform as a Service (PaaS) and Software as a Service (SaaS). In the IaaS model, a cloud provider delivers virtualized computing resources over the internet. The customer rents raw infrastructure: virtual machines (VMs), bare-metal servers, block and object storage, virtual networks, firewalls, and load balancers. The provider owns and maintains the physical hardware, the hypervisor, and the underlying network fabric.
The customer is responsible for everything above the hypervisor. This includes deploying and patching operating systems, installing middleware and runtimes, managing application code, and configuring network rules and security groups. IaaS gives the customer nearly full administrative control over the virtual environment, comparable to running a physical data center but without the capital expense of buying hardware. Resources are provisioned via APIs, command-line tools, or web consoles, and are typically billed on a per-hour or per-second basis.
IaaS is commonly used for lift-and-shift migrations of legacy applications, burst computing for variable workloads, disaster recovery hosting, and development/test environments where teams need complete control. Major vendors include Amazon Web Services (EC2, EBS, VPC), Microsoft Azure (Virtual Machines, Virtual Network), Google Cloud (Compute Engine, Persistent Disk), and DigitalOcean. The NIST SP 800-145 standard formally defines IaaS as part of its cloud computing taxonomy, published in 2011.
Key facts
- Customer manages the OS, middleware, and applications; provider manages physical hardware and virtualization layer.
- Resources are metered and billed on consumption, typically per second or per hour.
- IaaS uses virtualization (hypervisor) to isolate tenants on shared physical infrastructure.
- APIs and IaC tools like Terraform automate provisioning of IaaS resources.
- NIST SP 800-145 defines IaaS as the capability to provision processing, storage, networks, and other fundamental computing resources.
How it works in practice
Related terms
References
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