Why do I have 3 threads here?

Question

Well, I've come to my wit's end: I would say it is 2 threads here. Why should I have three I don't know.

public class ParallelProgramming {

    public static void main(String[] args) {
        Thrd firstThread = new Thrd("FirstThread.txt");
        firstThread.start();
        Thrd secondThread = new Thrd("SecondThread.txt");        
        secondThread.start();
    } // main
} // class



public class Thrd extends Thread {
String file;
    public Thrd(String file) {
        this.file = file;
    }


    @Override
    public void run(){
        <read the file line by line>
    }
}

Answer 1

Because the two threads are started by the main thread which is created when you start the application (in some cases, it's called UI thread too).

This thread runs main method.

Answer 2

In every java application there is a main thread. It executes the program. It can create new threads as well.