abstract class
abstract
abstract keyword
abstract method
abstract operation
as operator
as
base-class reference
concrete class
derived-class reference
downcasting
dynamic binding
GetType method of class object
GetType
object
implement an interface
inlining code
interface declaration
interface inheritance
interface keyword
interface
is-a relationship
is operator
is
late binding
polymorphism
realization
sealed class
sealed
sealed method
static binding
Type class
Type