What methods exist for creating and launching threads in an application?

In Java, there are several ways to create and start a thread (execution thread):

1. Extending the Thread class

class MyThread extends Thread {
    public void run() {
        System.out.println("Thread started");
    }
}

MyThread t = new MyThread();
t.start();

2. Implementing the Runnable interface

class MyRunnable implements Runnable {
    public void run() {
        System.out.println("Thread started");
    }
}

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

3. Using a lambda expression (Java 8+)

Thread t = new Thread(() -> System.out.println("Thread started"));
t.start();

Starting a thread is done by calling the start() method, which in turn calls the run() method in a new thread.