A barcode reader is a device that scans and interprets barcodes, which are patterns of parallel lines or squares that represent data. These readers can be handheld or fixed, and they use light sensors to capture the barcode's information. Once scanned, the reader converts the visual data into a digital format that can be processed by a computer or point-of-sale system. Barcode readers are commonly used in retail, inventory management, and logistics to track products and streamline operations. They help reduce human error and speed up transactions by quickly retrieving product information, such as price and stock levels, from a connected database.