What is Infrastructure as a Service?

Infrastructure as a Service, usually written as IaaS, is the rental version of the data centre. Instead of buying hardware and keeping it running, you rent virtual machines, storage, and networking from a provider and pay for what you use. The provider keeps the lights on: power, cooling, racks, the physical machines themselves.

What changes when you move to IaaS

With your own hardware, a new server is a project. You specify it, order it, rack it, cable it, image it, connect it, and the timeline runs in days or weeks. With IaaS, a new virtual machine is a configuration change. That speed is the point of the model. You can resize a machine when a promotion starts, add storage when a team needs it, and let it go again when the demand settles. On your own hardware, each of those is a conversation with a procurement lead. With IaaS, it is a form you fill in.

The ownership line moves too, and it is easy to miss. With your own server, the operating system, the network configuration, the applications, and the data are all yours to run. With IaaS, none of that changes. The provider takes the physical infrastructure underneath, and everything above it is still your job.

Common use cases

Teams reach for IaaS when the workloads are variable and paying month to month beats committing to multi-year hardware. It shows up as development and testing environments that get created and torn down frequently. Web applications that absorb seasonal traffic. Workloads that need specific networking, such as isolated subnets or private connections. Projects where a long hardware purchase does not fit the budget. And systems that need a spare copy running somewhere else for failover.

What IaaS is not

IaaS gives you infrastructure, not a finished platform. The operating system, the patches, and the application configuration remain your responsibility, although many providers offer managed add-ons that take some of that load off. It is also not a backup. Whatever you put on an IaaS volume should still be backed up outside it.

How to think about it

Before you compare IaaS to your current setup, look at how you actually run things today. How often does the capacity need to move? How long does a provisioning request take, from ask to working? What does the hardware that sits idle cost over a year? If the answers point to scaling that is slow, expensive, or both, IaaS is usually worth a pilot.