What's so great about Func<> delegate?

Question

Sorry if this is basic but I was trying to pick up on .Net 3.5.

Question: Is there anything great about Func<> and it\'s 5 overloads? From the looks of it, I can

Answer 1

Though it is an old thread I had to add that func<> and action<> also help us use covariance and contra variance.

http://msdn.microsoft.com/en-us/library/dd465122.aspx