Difference between Instance variables and Local variables

Posted in: Core Java Instance variables are declared inside a class but not inside a method

class Student{
    int num; // num is  instance variable
    public void showData{}
Local variables are declared inside a method including method arguments.
 
    public void sum(int a){
       int x = int a +  3;
      // a , x are local variables
   }

Points to Remember: 

1. When a method is called , a frame is created on the top of stack. 
2. Once a method has completed execution , flow of control returns to the calling method and its corresponding stack frame is flushed. 
3. Local variables are created in the stack Instance variables are created in the heap & are part of the object they belong to. 
4. Reference variables are created in the stack.