A barcode reader is a device that scans and interprets barcodes, which are patterns of parallel lines or squares that represent data. These readers use a light source, typically a laser or LED, to illuminate the barcode and a sensor to capture the reflected light. The information encoded in the barcode is then decoded and sent to a computer or point-of-sale system for processing. Barcode readers are commonly used in various industries, including retail, logistics, and healthcare, to track products, manage inventory, and streamline operations. They can be handheld or fixed, and some modern versions can even read barcodes from mobile devices, enhancing their versatility and efficiency.