title: Multithreading in java thread declaration
body: <p>These are few lines from my code:</p>
  
  <pre><code>class abc {
      public static void main(String br[]){
          Age age=new Age(21);
          Thread th1=new Man("Thread1",age);
          Thread th2=new Woman("Thread2",age);
          th1.start();
          th2.start();
      }
  }
  
  class Age
  { 
      int age;
      Age(int a) {
          this.age=a;
      }
  }
  
  class Man extends Thread()
  {
      Age age;
      Man(String name,Age age)
      {
          super(name);
          this.age=age;
      }
  } 
  </code></pre>
  
  <p>Woman class is exactly the same.</p>
  
  <p>I have three classes Age,Man,Woman. Can anyone explain what is happening in 2nd and 3rd line? I mean, what is the calling object of the class? What is the calling object of each thread? Also, if I use <code>this</code> in my <code>Man</code> class, what object will it refer to-the calling object or the <code>age</code> 21?</p>