I'm a newbie to java and I have the following Q -

class mythread implements Runnable {

.
.
.

}

scenario 1

mythread my = new mythread();
Thread t1 = new Thread(my);
Thread t2 = new Thread(my);
t1.start();
t2.start();

scenario 2

mythread my1 = new mythread();
mythread my2 = new mythread();
Thread t1 = new Thread(my1);
Thread t2 = new Thread(my2);
t1.start();
t2.start();

Whats the difference b/w scenario 1 and 2 ?. I'm kind of confused here.
Debugger shows me that two threads are created in both scenarios.

-j