A barcode scanner is simply an input device, like a keyboard. The scanner reads or “scans” the black and white lines by illuminating it with light which is reflected back into the decoder cell which decodes the analogue signal and converts it into digital text for your computer system. Barcode scanning should not be confused with barcode reading via image capture. Recent developments have seen barcodes read via image capture rather than scanning extending the reading to 2D barcodes, which traditional laser scanners cannot read.