what is os?@Explain JDK, JRE and JVM?@Explain public static void main(String args[]) in Java@ Why Java is platform independent?@Why Java is not 100% Object-oriented?@What are wrapper classes in Java?@What are constructors in Java?@What is singleton class in Java and how can we make a class singleton?@What is the difference between Array list and vector in Java?@What is the difference between equals() and == in Java?@What are the differences between Heap and Stack Memory in Java?@what is os?@Explain JDK, JRE and JVM?@Explain public static void main(String args[]) in Java@Why Java is platform independent?@Why Java is not 100% Object-oriented?@What are wrapper classes in Java?@What are constructors in Java?@What is singleton class in Java and how can we make a class singleton?@What is the difference between Array list and vector in Java?@What is the difference between equals() and == in Java?@What are the differences between Heap and Stack Memory in Java?@What is constructor @