I will describe how cloud systems deliver computing resources and identify the main models that power modern IT infrastructure.
“List every online tool you used before 1 p.m. today. Which ones run on someone else’s computers?”
| Model | Description | Example | What You Manage |
|---|---|---|---|
| IaaS (Infrastructure as a Service) | Virtualized computing resources—servers, storage, networking. | Google Compute Engine / AWS EC2 | OS, apps, data |
| PaaS (Platform as a Service) | Complete environment for developers — runtime, databases, tools. | App Engine / Azure Functions | Code + data |
| SaaS (Software as a Service) | Ready-to-use applications via browser. | Gmail, Google Drive, Salesforce | Only usage + data |
Analogy: