// "static void main" must be defined in a public class.
    class MyThread extends Thread{
        public void run(){
            for(int i=0;i<5;i++)
                System.out.println("MyThread");
        }
    }
    public class CreateThread {
        public static void main(String[] args) {
            MyThread t=new MyThread();

    // by calling this, user defined thread is registered into thread scheduler, starts executing thread t
    t.start();
    
    // by default, user created thread name will be "Thread-n"
    System.out.println("MyThread name is "+t);  // MyThread name is Thread[Thread-0,5,]
    
    // setName will change a thread t's name
    t.setName("sravya");
    System.out.println("MyThread name is "+t);  // MyThread name is Thread[sravya,5,]
    
    System.out.println("main thread");
    // Thread.currentThread() will give current thread, getName() fetches the name
    System.out.println("main thread name is "+Thread.currentThread().getName());    // main thread name is main

     }
    }

MyThread
MyThread
MyThread
MyThread
MyThread
MyThread name is Thread[Thread-0,5,]
MyThread name is Thread[sravya,5,]
main thread
main thread name is main

    // "static void main" must be defined in a public class.
    class MyThread implements Runnable{
        public void run(){
            for(int i=0;i<5;i++)
                System.out.println("MyThread");
        }
    }
    public class CreateThreadRunnable {
        public static void main(String[] args) {

            MyThread r=new MyThread();

            Thread t=new Thread(r);
            t.start();

            System.out.println("MyThread name is "+t);  // MyThread name is Thread[Thread-0,5,main]
            t.setName("sravya");
            System.out.println("MyThread name is "+t);  // MyThread name is Thread[sravya,5,main]

        }
    }

    MyThread name is Thread[Thread-0,5,main]
    MyThread
    MyThread
    MyThread
    MyThread
    MyThread
    MyThread name is Thread[sravya,5,main]
    main thread
    main thread name is main