Boxing and Un-Boxing:

Implicit(automatic) conversion of value type to reference type is known as Boxing And Explicit (manual) conversion of Reference type to value type is said to be Un-boxing. (conversion of Integer variable to object type)

Class

Class is concrete representation of an entity. It represents a group of objects, which posses similar attributes and behavior.
Provides Abstraction and Encapsulations. A category name that can be given to group of objects of similar kind.

Destructor/Finalize

Called by GC just before object is being reclaimed by GC.

Constructor

Special Method Always called whenever an instance of the class is created.

Static Variable and Its Life-Time

VB.NET: Public Shared VAR As Type.
C#: public static Type VAR;
Life time is till the class is in memory.

What is a Delegate?

A strongly typed function pointer. A delegate object encapsulates a reference to a method. When actual function needs to be called will be decided at run-time.

Identifiers/Access Specifies and scope

VB.NET: Private, Protected, Friend, Protected Friend, Public.
C#: private, protected, internal, protected internal, public.