A UPC, or Universal Product Code, is a unique barcode used to identify products in stores. It consists of 12 digits and is typically found on product packaging. Retailers scan the UPC at checkout to quickly retrieve product information and prices, making the purchasing process more efficient. The UPC system was introduced in the 1970s to streamline inventory management and sales tracking. Each UPC is assigned to a specific product, allowing manufacturers and retailers to monitor stock levels and sales trends. This system has become essential in modern retail, facilitating easier transactions and better supply chain management.