Task Queue Java API

Question

What is the purpose of Task Queue Java API? How does it work, and where should it be used?

Answer 1

The homepage looks pretty unambiguous:

With the Task Queue API, applications can perform work outside of a user request but initiated by a user request. If an app needs to execute some background work, it may use the Task Queue API to organize that work into small, discrete units, called Tasks. The app then inserts these Tasks into one or more Queues. App Engine automatically detects new Tasks and executes them when system resources permit.