C # vitural

By default, derived class classes inherit properties and methods from their base classes, and if the inherited property or method requires different behavior in the derived class, you can override it to define a new implementation of the property or method in the derived class. At this point in the base class, the property or method must be decorated with the virtual keyword. The virtual keyword can be overridden in a derived class when it is used to specify a property or method. A method or property with the virtual keyword is called a dummy member.
Class A
{
    public virtual void F () {}
}

Class B:a
{
    public override void F () {}
}

C # vitural