MyThread.java

public class MyThread extends Thread{
   public void run(){
      System.out.println("My Thread Running: " + Thread.currentThread().getName());
   }
 }
public class MyRunnable implements Runnable{
  public void run(){
    System.out.println("My Runnable Running: " + Thread.currentThread().getName());
  }
}

...
...
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public static void main(String[] args) {
  Thread mythread = new MyThread();
  mythread.setName("mythread");
  mythread.start();
  
 	/*
	* An instance of java.lang.Thread represent a thread but it needs a
	* task to execute, which is an instance of interface java.lang.Runnable
	*/
  Thread myrunnable = new Thread(new MyRunnable(),"mythreadwithrunnable");
  myrunnable.start();

 	/*
	* Since Runnable is a functional interface, that's why it can be passed
	* as a lambda expression
	*/
  Thread thread = new Thread(() - >  System.out.println("Thread running.."));
  thread.start();
}