Cloud computing is the delivery of computing services — servers, storage, databases, networking, and software — over the internet, paid for as they are consumed. The AZ-900 exam starts here, so a precise definition matters more than a vague impression.
From Owned Hardware to Rented Capability
In a traditional data center, an organization buys servers, houses them, powers them, and replaces them as they age. In the cloud, a provider like Microsoft owns that hardware and rents capacity on demand. You trade large upfront purchases for operational spending, and you can scale from one virtual machine to thousands without buying anything physical.
The Benefits Azure Emphasizes
Microsoft frames cloud value around high availability, scalability, elasticity, reliability, predictability, security, and manageability. Scalability means adding capacity as demand grows; elasticity means shrinking it again when demand falls. Reliability comes from redundant infrastructure spread across many facilities, and predictability covers both performance and cost forecasting. Expect questions that ask which benefit a short scenario is describing.
Why Definitions Decide Exam Questions
Fundamentals-level scenario questions often hinge on distinguishing similar terms. Elasticity versus scalability is the classic pair, but agility, fault tolerance, and disaster recovery also appear in answer choices together. Practice restating each term in one sentence of your own words; if you cannot, you have memorized a phrase rather than understood the concept, and careful wording will trip you up.
Action Step
Write one-sentence definitions of scalability, elasticity, high availability, reliability, and agility without looking at notes. Then compare each against the cloud concepts pages on Microsoft Learn and correct any that drifted. Keep the corrected list as a flashcard set and review it before each study session this week.
Independent exam-preparation content only — not affiliated with or endorsed by the certification body, and no exam result is guaranteed. This course does not itself certify anyone. Verify current exam objectives on the official site before scheduling your exam.