Bar code is machine-readable representation of information usually dark ink on a light background to create high and low reflectance, which is converted to 1's and 0's. Originally bar codes store data in the widths and spacings of printed parallel lines, but today they also come in patterns of dots, concentric circles, and text codes hidden within images. Barcodes can be read by optical scanners called barcode readers or scanned from an image by special software. Barcodes are widely used to implement Auto ID Data Capture (AIDC) systems that improve the speed and accuracy of computer data entry. An advantage over other methods of AIDC is that it is less expensive to implement. Bar codes are a unique bar or space patterns, which represent various alphanumeric characters. Bar code is the system that consists of bar code label, bar code scanner, and bar code printer. Contact bar code scanners use pen or wand to read labels. Noncontact bar code scanners include fixed beam, moving beam, and omni directional beams. 1-D codes are most common; 2-D codes enable much greater data storage capability.