Serverless — Azure Functions
Run event-triggered code with automatic scaling and consumption-based billing.
Azure Functions is Azure's serverless compute: you write a function with a trigger and Azure runs it on demand, scaling out automatically. A defining feature is the trigger/binding model — a function has exactly one trigger (HTTP, Timer, Queue/Service Bus message, Blob created, Event Grid/Hub event, Cosmos DB change feed) and optional input/output bindings that wire it to other services declaratively, reducing boilerplate for reading and writing data.
A vending machine wired to the building: a coin (trigger) makes it act, and chutes connect it directly to supply and delivery (bindings) so it does not need its own plumbing. It powers down completely between customers and costs nothing while idle.