Azure Functions implement event-driven serverless compute. Function App hosts multiple functions sharing configuration. Triggers start function execution: HTTP, Timer, Blob, Queue. Bindings connect functions to data sources declaratively. Input bindings read data, output bindings write data. Durable Functions orchestrate complex workflows with state. Consumption plan scales automatically and charges per execution. Premium plan provides pre-warmed instances and VNET integration. App Service plan runs on dedicated infrastructure. Supported languages include C#, JavaScript, Python, Java. Functions can be developed locally with Azure Functions Core Tools. HTTP triggers expose REST endpoints with route customization. Timer triggers run on cron schedules. Blob triggers respond to storage events. Queue triggers process Service Bus messages. Function Proxies route and transform requests. Application Insights monitors function performance and errors. Managed identities handle authentication without secrets. Deployment slots enable staging environments. Cold starts affect consumption . Azure Functions integrate deeply with the Azure ecosystem.