The Point of Sale (POS) system is where retail transactions are completed. It's the hardware and software used for checkouts - the point at which a customer makes a payment to the merchant in exchange for goods. Example: A touchscreen POS system in a supermarket. Use Case: Facilitating sales transactions, processing credit card payments, and managing customer receipts.

A Stock Keeping Unit (SKU) is a unique identifier for each distinct product and service for sale. It helps in tracking inventory and sales. Typically, an SKU is associated with any purchasable item in a store or catalog. Example: A specific model of a smartphone with a unique color and storage capacity. Use Case: Managing inventory levels, identifying sales trends, and reordering products.