The task parallel library (TPL) is a set of public types and APIs.
The vision behind the TPL is for the developers to be able to maximize the performance of code while not having to worry about the nitty gritties of threading. TPL makes us productive by

• Simplifying the process of adding parallelism and concurrency to applications.
• Scaling the degree of concurrency dynamically.
• Handling partitioning of the work .
• Scheduling threads on the ThreadPool
• Allowing for cancellation of the task.
• Handles state management
  

Cancellation

What is System.Threading.Interlocked?

Interlocked class provides atomic operations for variables that are shared by multiple threads.

Pass state to continuation tasks