Zach made this UML shpping Cart Class diagram by adding multiple different classes. He used his user class , which has attributes for user ID, password, login status,and register date. As well he designed the customer class, which is a "child" the user class. This means that the customer would get all the attributes and methods of the User Class. The other Classes that Zach made are shipping info and older to disingish the different types of relationhips than the main class the shopping cart has. Public visibility is another attribute or method that could be accessed by another class. You will Know when it's public if it has the plus sign next to it. Private visibility is another attribute or method that cannot be accsesessed by another class or subclass. You can tell if it's private when it has the Minus sign next to it. Method means the behavior of the class. Also, Inheritence is when a child class Inherits the attributes and methods of the parent class.