What is Func, how and when is it used

Question

What is Func<> and what is it used for?

Answer 1

Both C# and Java don't have plain functions only member functions (aka methods). And the methods are not first-class citizens. First-class functions allow us to create beautiful and powerful code, as seen in F# or Clojure languages. (For instance, first-class functions can be passed as parameters and can return functions.) Java and C# ameliorate this somewhat with interfaces/delegates.

Func randInt = (n1, n2) => new Random().Next(n1, n2); 

So, Func is a built-in delegate which brings some functional programming features and helps reduce code verbosity.