Durable Function types

You can use three durable function types: Client, Orchestrator, and Activity.

• Client functions are the entry point for creating an instance of a Durable Functions orchestration. They can run in response to an event from many sources, such as a new HTTP request arriving, a message being posted to a message queue, an event arriving in an event stream. You can write them in any of the supported languages.
• Orchestrator functions describe how actions are executed and the order in which they are run. You write the orchestration logic in code (C# or JavaScript).
• Activity functions are the basic units of work in a durable function orchestration. An activity function contains the actual work performed by the tasks being orchestrated.