UNITECH K2724U-B Keyboard, 104 Keys, Dual Track MSR, 9 Pin Bar Code Port, Black

this is barcodes in one lesson barcodes are found on virtually all products that you see in any store when a laser from a computer scans a barcode it's actually scanning through a series of 95 evenly spaced columns and checking to see if each one of those columns is reflecting a lot of laser light or virtually none computers only understand ones and zeros so any of the columns that reflect virtually no light are considered a one and any of the columns that reflect a lot of light are considered zero probably the reverse of what you might expect so in this example the computer begins reading the columns from left to right the first column reflects virtually no light so it considers that a 1 the next column reflects a lot of light so it considers that a 0 the third column is like the first it reflects virtually no light so it also considers that a 1 the fourth fifth and sixth columns all r