Product identifiers are unique codes or numbers assigned to specific items to distinguish them from others. These identifiers help businesses and consumers track products, manage inventory, and facilitate sales. Common examples include Universal Product Codes (UPCs) and International Standard Book Numbers (ISBNs). These codes are essential for various industries, including retail and publishing, as they streamline processes like ordering and shipping. By using product identifiers, companies can ensure accurate product information and improve customer experience, making it easier for shoppers to find and purchase the items they need.