<P> A barcode reader (or barcode scanner) is an electronic device that can read and output printed barcodes to a computer . Like a flatbed scanner, it consists of a light source, a lens and a light sensor translating optical impulses into electrical ones . Additionally, nearly all barcode readers contain decoder circuitry analyzing the barcode's image data provided by the sensor and sending the barcode's content to the scanner's output port . </P> <P> Barcode readers can be differentiated by technologies as follows: </P>

When is bar code reader used for input and how
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