The Universal Product Code (UPC), better known as a bar code, is one of the most common methods that retailers use to manage, price and scan products for sale. Bar codes are printed on most packaged products. Reading a bar code requires a bar code scanner connected to a database with the product information. Determining the price of an item with a bar code is simple.
Look around the store for a customer-use scanner. Many retailers have one or several. Typically, they are labeled or marked, but ask an employee if you can't find the scanner.
Hold the bar code of the product under the laser portion of the customer-use scanner. The scanner's screen will display the price.
Bring the product to a cashier and ask her to scan it for you at the register in you can't find a consumer scanner. Cashiers can check the price before you buy an item.
Scan the bar code of the product using your iPhone and the RedLaser application (available at the App Store for $1.99). This application uses your iPhone's camera to scan products and relays the information, giving you product information like the product's name and cost. You must have an iPhone to use RedLaser.