Microsoft has released async/await feature in .Net 4.5. It’s a really great stuff as it significantly simplifies one of the most painful areas - asynchronous programming. Before that, Task Parallel Library (TPL) and Parallel LINQ (PLINQ) were released in .Net 4.0. They address problems with parallel programming - another painful area in .Net.

I often see programmers struggling with a question when to use each of these features. Let’s step back and recall what does it actually mean to be asynchronous or parallel.