A barcode reader is a device that scans and interprets barcodes, which are patterns of parallel lines and spaces 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 streamline inventory management and sales transactions. They help improve efficiency by quickly identifying products, reducing human error, and speeding up checkout processes.