these are just reference to the methods and delegates are 
used at the bottom of events.

Delegates are like function pointer in c++ with type-safe.
They can be used in 2 situations 
1. callback methods
2. eventHandler

Delegate hold reference to another function or method

1. Delegates holds reference to a method
2. Delegates are objects which points towards a function 
which matches its signature
3. Delegates are reference type used to encapsulate method 
with specific signature
4. Delegates are typesafe and secure

//declaring a delegate 

delegate void SampleDelegate(string message)

//declaring delegate with same signature

static void SampleDelegateMethod(string message)
{
console.writeline(message);
}

//creating delegate method

SampleDelegate d1 = new SampleDelegateMethod();

//invoking method

d1(message);

Delegate is a strongly typed function pointer. A delegate 
object encapsulates a reference to a method

delegates holds the reference of the function
then you can call that function through the delegate object

main benifit of delegate is that you can make difference 
between class objects
you can assign the different -2 methods to different-2 
object of same class

delegate is a reference type which is used to encapsulate a
method with specific signature.
delegates are 2 types
1.single cast delegate 
2.multi caste delegate.
Adv:
1.it will improve the performance of the application.