IaaS, PaaS, and SaaS

Think in layers of responsibility

Cloud offerings are often grouped by how much of the stack the provider runs for you. The higher the layer, the less you configure yourself—and the less low-level control you keep.

Name the three models

• IaaS (Infrastructure as a Service): you rent virtual machines, disks, and networks and install the OS and apps
• PaaS (Platform as a Service): you deploy code or containers; the provider handles runtime, scaling glue, and much of the OS
• SaaS (Software as a Service): you use a finished application such as email or a CRM in a browser

Match the model to the job

A learning lab or custom server stack often starts on IaaS. A web API without wanting to patch Linux may fit PaaS. Day-to-day tools like Google Workspace or Microsoft 365 are SaaS. Many real systems mix models—for example IaaS databases next to a SaaS analytics product.

See the names shift by vendor

Roughly: AWS EC2, Azure Virtual Machines, and GCP Compute Engine are IaaS compute. Managed app platforms and serverless runtimes sit closer to PaaS. Knowing the category helps you compare docs across clouds.