Объясните пожалуйста)

package com.javarush.task.task04.task0402;

/*
Цена яблок
*/

public class Solution {
    public static void main(String[] args) {
        Apple apple = new Apple();
        apple.addPrice(50);
        Apple apple2 = new Apple();
        apple2.addPrice(12);
        System.out.println("Стоимость яблок " + Apple.applesPrice);
    }

    public static class Apple {
        public static int applesPrice = 0;

        public static void addPrice(int applesStor) {
            //напишите тут ваш код

            Apple.applesPrice = Apple.applesPrice + Apple.applesPrice;
            //Apple.applesPrice = Apple.applesPrice + applesPrice;
        }
    }
}

Apple.applesPrice

this.applesPrice

this.applesPrice =  this.applesPrice +applesPrice;