what is different between new , virtual , new virtual ,and override in inheritance ?

class Base
{
    public new virtual void Show()
    {
        Console.WriteLine("Base ");
    }
}
class Child1 : Base
{
    public override void Show()
    {
        Console.WriteLine("Drived1 ");
    }
}
class Child2 : Child1
{
    public virtual void Show()
    {
        Console.WriteLine("Drived2 ");
    }
}
class Child3 : Child1
{
    public new void Show()
    {
        Console.WriteLine("Drived3 ");
    }
}