What is Thread getUncaughtExceptionHandler() in Java?

// Load library
import java.lang.Thread;
public class Thread_example implements Runnable {
   Thread thrd;
   public Thread_example() {
      thrd = new Thread(this);
      // calling run() method
      thrd.start();
   }
   public void run() {
      // printing the name of thread
      System.out.println("Thread :" + thrd.getName());
      /* will return the handler invoked when the thread is stopped because of an uncaught exception. */
      Thread.UncaughtExceptionHandler handler = 
      thrd.getUncaughtExceptionHandler();
      System.out.println(handler);
   }
   public static void main(String[] args) {
      new Thread_example();
      new Thread_example();
   }
}