Cloud concepts
⏱ ~3-min readAceMark Guide
What this topic is really about
In SaaS the provider manages everything except the customer data and identity — Microsoft 365 itself is SaaS. PaaS leaves the customer responsible for the app code, IaaS leaves them responsible for the OS and runtime, and on-premises means they own it all.
Cloud "as a service" models shift spending from large up-front capital expenditure (CapEx) on hardware to ongoing operational expenditure (OpEx) based on consumption. They still require user accounts, licensing, and internet connectivity.
See the mechanism
In SaaS the provider manages everything except the customer data and identity — Microsoft 365 itself is SaaS. A diagram for this topic isn't available yet — the worked example below walks the same reasoning step by step.
An exam-style question, fully explained
Which cloud service model gives the customer the LEAST responsibility for the underlying infrastructure?
- Identify what the question tests: Which cloud service model gives the customer the LEAST responsibility for the underlying infrastructure.
- In SaaS the provider manages everything except the customer data and identity — Microsoft 365 itself is SaaS.
- PaaS leaves the customer responsible for the app code, IaaS leaves them responsible for the OS and runtime, and on-premises means they own it all.
Traps the examiner sets
- Read each option carefully — distractors on Cloud concepts are designed to look plausible.
- Re-check the exact wording of the question stem before committing to an answer.
- Watch the qualifiers ("always", "only", "except") that flip a correct-looking option.
Test your recall
Answer each from memory — you'll see instantly whether you're right and why.
Run a focused 10-question mini-mock on Cloud concepts and see it stick.
Practice more of this topic →