sleep() in java Thread class

Thread class sleep method document:

class Thread
{
	public static void sleep(long millis) throws InterruptedException
        {
                    Causes the currently executing thread to sleep (temporarily cease execution) for the specified number of milliseconds
	}
}

Program Code:

class Custom extends Thread
{
	public void run()
	{
		for (int i=1 ; i<=10 ; i++)
		{
			System.out.println("Custom : " + i);
			try{
				Thread.sleep(1000);
			}catch(InterruptedException e){ }
		}
	}
}
class Default 
{
	public static void main(String[] args) 
	{
		Custom th = new Custom();
		th.start();
		
		for (int j=1 ; j<=10 ; j++)
		{
			System.out.println("Default : " + j);
			try{
				Thread.sleep(1000);
			}catch(InterruptedException e){ }
		}
	}
}

• In single threaded, execution starts @ default thread and ends @ the same thread.
• In multi threaded, any thread can completes the execution while all the threads executing parallel.

class Custom extends Thread
{
	public void run()
	{
		for (int i=1 ; i<=10 ; i++)
		{
			System.out.println("Custom : " + i);
			try{
				Thread.sleep(200);
			}catch(InterruptedException e){ }
		}
		System.out.println("Custom thread completed...");
	}
}
class Default 
{
	public static void main(String[] args) 
	{
		Custom th = new Custom();
		th.start();
		
		for (int j=1 ; j<=10 ; j++)
		{
			System.out.println("Default : " + j);
			try{
				Thread.sleep(1000);
			}catch(InterruptedException e){ }
		}
		System.out.println("Default thread completed...");
	}
}