Delegate in c#

            Delegate                                                

  Delegate is a special data type that hold the address or reference of a function.

There are two type of delegate.
1)single cast delegate.
2)multi cast delegate.

                    Single cast delegate.

If we are using delegate object to store single function, then we said that it is single cast delegate.

                     Multi cast delegate.

If we are using delegate object to store multiple function, then we easily said that it is multi delegate.

                         General syntax of delegate

#create delegate.

Access specifiers delegate name of delegate.
E.g:-
Public delegate my del();
#procedure to create object of delegate and hold function into it.
My del obj1=new My del ();
#calling of function using delegate object.
Obj1();= fun 1();

explanation of definition of ado.net

Ado means active data object and ado is replaced by ado.net .Ado.net is fully based on oops concept.
ADO.NET is a set of computer software components that programmers can use to access data and data services based on disconnected DataSets and XML. It is a part of the base class library that is included with the Microsoft .NET Framework. It is commonly used by programmers to access and modify data stored in relational database systems, though it can also access data in non-relational sources. ADO.NET is sometimes considered an active x data object.

difference between interface and abstract class.

Difference between interface and abstract class

Interface provide pure abstract methods.

Abstract class provide concrete classes.

Interface provide multiple inheritance.

Abstract class don't provide multiple inheritance.

We cannot create object of interface, we create only reference variable of interface.

We create object of abstract class.

We cannot define data field within interface.

In abstract class we have to define data field. 

We cannot use any access specifier within interface.

We can use access specifier with abstract class.