Azure Functions are essentially a managed service for WebJobs SDK that provide similar functionality but in a fully serverless environment.

WebJobs provide a means to run background tasks in the context of a Web App, Mobile App, or API App. With them, you can upload a script such as PowerShell or a command file and have them run on a schedule (https://azure.microsoft.com/en-us/documentation/articles/websites-webjobs-resources/).

At the very basic level, Azure Functions can be thought to be defined by:

Events + Code + Data = Function App 

The key part of a Function App is the initial trigger that starts the process of running the code contained within a function. This trigger can be in the form of an input event, such as a message being written to a queue, or a timed event. A function can have a number of outputs that send data and information to a range of endpoints.

A Function App represents a unit of computing, and it can contain a number of functions, each...