Task-based Async Pattern (TAP)

Introduced with Dot.net 4.5 , Task-based Asynchronous Pattern (TAP) is based on the Task and Task<TResult> types in the System.Threading.Tasks namespace, which are used to represent arbitrary asynchronous operations. TAP is the recommended asynchronous design pattern for new development.

http://msdn.microsoft.com/en-in/library/hh873175.aspx