CreateThread.java

// 1. create a sub class inherent to Thread class
static class MyThread extends Thread {

    @Override
    public void run() {
        System.out.println("Hello : "+Thread.currentThread().getName());
    }
}
MyThread myThread = new MyThread();
myThread.start();

// 2. implement Runnable
Thread thread = new Thread(new Runnable() {
    @Override
    public void run() {
        System.out.println("Hello : "+ Thread.currentThread().getName());
    }
});

// 2-1 implement Runnable in functional programming
Thread thread = new Thread(() -> System.out.println("Hello : "+ Thread.currentThread().getName()));

thread.start();