Introduction to Azure Functions

Azure Functions is Azure's event-driven, serverless compute service. It lets you run small pieces of code — called functions — without provisioning or managing servers. Each function is triggered by an event, executes its logic, and returns a result. This lesson covers the fundamentals: creating your first function, understanding the project structure, supported languages, and the development workflow.

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What is an Azure Function?

An Azure Function is a single unit of execution — a method or function in code — that runs in response to a trigger. Functions are:

• Stateless — each invocation is independent (unless using Durable Functions)
• Short-lived — designed to execute quickly and return
• Event-driven — always started by a trigger, never by polling or manual start
• Scalable — the platform can run thousands of instances simultaneously

A function app is the container that hosts one or more related functions. It provides the execution context, configuration, and deployment unit. All functions within a function app share the same configuration, connection strings, and pricing plan.

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Supported Languages and Runtimes

Azure Functions supports multiple languages across two programming models:

In-Process (Classic)