What is IaaS, PaaS and SaaS?
Three ways to rent cloud computing, from raw servers (IaaS) to a platform for your code (PaaS) to a finished app (SaaS).
In plain English
The letters tell you how much the provider manages and how much is left for you. With IaaS you rent virtual machines, storage and networks and manage the operating system and everything above it. With PaaS the provider also runs the operating system and runtime, so you only deploy code and data. With SaaS the provider runs everything and you just use the software.
Example
A virtual machine you configure yourself is IaaS. A managed service where you upload your web app and it runs is PaaS. Email you open in a browser is SaaS.
Easy to confuse with
- Shared responsibility model: The service models decide who manages which layer. The shared responsibility model describes who is accountable for security at each layer.
Where you will meet it
This idea belongs to the subject area of these practice tests. We do not publish or predict real exam questions.
Related terms
- Shared responsibility model: The cloud provider secures the cloud itself, and you secure what you put in it.
- High availability: Designing a system so it keeps working when a part of it fails.
Test yourself
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Browse practice testsAll glossary termsWritten and checked by the Be Ready Education team, last reviewed 2 November 2026. General study information, not professional advice. Providers change names and rules, so confirm details on the official documentation. Not affiliated with, endorsed by or sponsored by any certification vendor or exam body. Certification names, exam codes and product names are trademarks of their respective owners and are used only to identify the exam a practice product prepares for. Our questions are original and are not actual exam questions.