Describe cloud concepts
Cloud Economics and Serverless
CoreRelate consumption and commitment choices to workload patterns, and recognize serverless execution.
Aligned to the AZ-900 skills measured as of July 20, 2026; product behavior verified August 23, 2026.
Why this matters
Fundamentals questions test whether a pricing approach follows usage and whether server management belongs to the customer—not memorized prices or implementation steps.
Must Know
- A consumption-based model measures usage and charges for the resources consumed, turning much technology spending into operating expense rather than a large upfront asset purchase.
- Pay-as-you-go provides flexibility for uncertain or short-lived demand. A time commitment can reduce eligible costs for predictable, sustained use but reduces flexibility.
- A pricing estimate depends on selected services, quantities, regions, duration, data transfer, and commercial choices. No model guarantees the lowest final bill.
- Serverless lets developers run event-driven code while the provider manages the servers and execution environment.
- Serverless does not mean physical servers cease to exist; it means the customer does not provision or manage them for that execution model.
Compare and Distinguish
- CapEx vs OpEx: upfront ownership of assets versus ongoing operating expense linked to service consumption.
- Pay-as-you-go vs commitment: flexibility for variable use versus potential savings for predictable use in exchange for a commitment.
- Consumption vs guaranteed savings: usage-linked billing can reduce unused capacity, but workload choices still determine total cost.
- Serverless vs VM: event-driven execution without guest-OS management versus a virtual machine whose guest environment the customer manages.
Scenario examples
- A development experiment uses pay-as-you-go so it can stop without a long commitment.
- A stable baseline is evaluated for commitment pricing while an unpredictable burst retains pay-as-you-go flexibility.
- An image-upload event triggers a short function without a team maintaining a guest operating system.
Exam traps
- Every cloud charge is not necessarily pure pay-as-you-go.
- A calculator estimate is not a guaranteed invoice.
- Serverless still runs on provider-managed infrastructure.
Key takeaways
- Match pricing to duration and predictability.
- Consumption links cost to measured use without guaranteeing the cheapest outcome.
- Serverless removes server management from the customer’s view, not servers from the provider.
Ready for the quiz?
- Which pattern favors pay-as-you-go?
- What trade-off accompanies a commitment?
- Why can serverless still involve physical servers?
Related objectives
- D1.1.S5 — Describe the consumption-based model
- D1.1.S6 — Compare cloud pricing models
- D1.1.S7 — Describe serverless