Answer 1

A virtual method is a method in a class that can be overridden. A subclass can override this method. Unlike an abstract method, a virtual method does not need to be overridden and has a body. Virtual functions are very useful for methods that don't exactly need implementation by the subclass.

Example:

Class A {
public virtual void myfunc() {}
//function without a body
}
Class B : A{
public override void myfunc() {
Console.Println("b");
}
}
Class C : A{
Void ex() {
//some other things
}
}