Which Azure compute service runs small pieces of code in response to events, scales automatically, and bills only for execution time?
A.Azure Virtual Machine Scale Sets
Scale Sets scale VMs — you pay for VM uptime, not per execution.
B.Azure Functions
Functions = event-driven serverless with per-execution billing. Correct.
C.Azure Batch
Batch runs large-scale parallel jobs on managed VM pools — not per-event serverless.
D.Azure SQL Database
SQL Database is a data platform, not compute for event handlers.
Why this answer
Azure Functions is the serverless compute service: event-driven, per-execution billing, automatic scale to zero — the purest 'pay only when code runs' model. Container Instances is also per-second but is for containers.
Correct answer: B · Last reviewed 2026-02-13
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