Delegates allow you to pass methods around like values.
For example, .Net has a method called Array.ForEach that takes a delegate and an array, and calls the delegate on each element of the array.
Therefore, you could write,
int[] arr = new int[] { 1, 2, 4, 8, 16, 32, 64 };
Array.ForEach(arr, new Action(Console.WriteLine));
This code will call Console.WriteLine for each number in the array.
There are many things you can do by making functions that take delegates, especially when combined with anonymous methods. For examples, look at LINQ.
