Cloud Concepts

The Six Benefits AZ-900 Names, and How to Tell Them Apart

Microsoft lists specific benefits and then asks which one a scenario describes. Several are close enough that guessing from intuition goes wrong, so learn the distinguishing phrase for each.

Exam tip. If the scenario mentions demand rising and falling on its own, choose elasticity. If it mentions surviving a failure, choose high availability.

Who Owns What, Row by Row

Microsoft's shared responsibility diagram is a table, and the exam asks you to read specific cells of it. Three rows are always yours, three are always Microsoft's, and three move with the service model.

Exam tip. Decide the service model first, then read the row. Answering from intuition is what makes these feel ambiguous.

The Words AZ-900 Uses Precisely, and the Ones It Confuses You With

This exam is unusually vocabulary-driven. Several wrong answers are near-synonyms of the right one, so knowing the exact distinction is worth more than any amount of hands-on intuition.

Exam tip. When two options both sound right, one of them is the near-synonym. Go back to these definitions rather than to intuition.

1. A company wants to reduce operational burden the most while still running its own custom application code. Which model should it prefer?

• A. Platform as a servicecorrect
• B. Infrastructure as a service
• C. Software as a service
• D. A private cloud

PaaS removes operating system and runtime management while still hosting the customer's code. SaaS would mean giving up the custom application entirely, and IaaS keeps the OS burden.

2. Which scenario is the strongest argument for a private rather than public cloud deployment?

• A. The organisation wants to launch new services faster
• B. A regulator requires that specific workloads run on hardware the organisation physically controlscorrect
• C. The organisation wants to reduce its capital expenditure
• D. The workload has highly variable demand

Physical control of the hardware is the requirement a public cloud cannot satisfy. Reducing capital spend, absorbing variable demand and moving faster are all arguments for public cloud rather than against it.

3. Which characteristic best describes the consumption-based pricing model used by public cloud providers?

• A. You pay only when a workload fails to meet its service level agreement
• B. You pay only for the resources you use, with no upfront capital purchase of hardwarecorrect
• C. You buy servers upfront and pay a fixed annual maintenance fee
• D. You pay a flat monthly fee regardless of usage

Consumption-based pricing converts capital expenditure into operating expenditure: you are billed for what you consume, and you stop paying when you stop using it. Fixed fees and upfront hardware purchases are the on-premises model the cloud replaces.