Bar code by the United States of N. T. Woodland first proposed in 1949. In recent years, with the growing popularity of computer applications, bar code application has been great development. Bar codes can be marked goods producer, manufacturer, product name, date of production, Books words, starting and ending location message, category, date and other information, which in many areas of commodity circulation, library management, telecommunications management, banking systems have been widely used bar code by a certain length, width ranging from digital lines and symbols, which is a use of ordinary printing process, through the optical scanning reading means reading computer graphic language. Barcode recent decades research and development of a data input technology and automatic identification technology, which reflects many categories of information, production companies, weight, amount, date of manufacture and circulation time of commodities.

Barcode one-dimensional bar codes and two-dimensional bar code. Barcode code system more consistent dimensional bar code has the UPC code, EAN code, the March codes, ISBN codes. Dimensional bar code is for a one-dimensional bar code information capacity of small flaws and narrow the barcode area and improve the ability to resist pollution and developed out of it with a one-dimensional bar code except that the text information to be bar codes, and its data can be applied not only in English, numbers, characters, symbols, each font can be even blank processing, information storage capacity of up to 1100 numbers (one-dimensional barcodes only 15 digits). In addition, the two-dimensional bar code can also use encryption technology, the security of the goods substantially increased.