A pricing model where you only pay for the resources you consume, for as long as you use them. No long-term contracts or upfront costs. It lets you optimize spend by turning off resources when they are not needed.
The baseline model in AZ-900 and CLF-C02. Azure and AWS also offer reserved pricing (1-3 years) with 40-72% discounts. Question: when is reserved better than on-demand? Answer: predictable workloads → reserved; spikes or testing → on-demand.
Pay-as-you-go is a concept that can show up on the exam. Check the full guide to see it in context.