Model responsible for the login of the application, no business logic besides authentication should be put on it
This model is the one that we should consider being the real user of our application, it contains all the data and history of a user in the application
Consists of one specific order, it has a list of order details and any other relevant information regarding that order
It is about one SKU in the order, it has the quantity of the item, and all the data about the SKU when the order was placed.
It is the distinct version of a product, it can have more specific information about that variantion of the product
The product, has all the fields in case the SKU didn't provide some of them it can be used as a fallback for that info.