These devices use a "pin-point" laser light source and a reciprocating mirror to scan the laser beam back and forth across the barcode. They use reflected light to decode a barcode image into the data that is contained in the barcode. Since the laser is a fairly intense light source, the operator does not need to place the scanner close to the barcode and can scan barcodes that are about 10-30cm away from the scanner. Some industrial laser scanners can read a barcode that is a very long distance away (2 metres).
