polymorphism

[Bsbosa.com]

Defination: "Through inheritance, a class can be used as more than one type; it can be used as its own type, any base types, or any interface type if it implements interfaces. This is called polymorphism".

But does it mean changing a behaviour of a method in a drieved class also means polymorphism. e.g

public class BaseClass
{
public virtual void DoWork() { }
public virtual int WorkProperty
{
get { return 0; }
}
}
public class DerivedClass : BaseClass
{
public override void DoWork() { }
public override int WorkProperty
{
get { return 0; }
}
}