The code rule is the main basis for the identification of the code. Bar code consists of a set of rules, empty and its corresponding character.
Such as daily commodity packaging bar code is 39 bar code. Its information storage capacity can only store a code, when used by this code and obtain computer network number. According to the QR code is developed in the recent years, it can in the limited space in the store more information, including text, image, fingerprint, signature, etc., and can be used without computer. At present, the common code of have the following: (39 Barcode, 128 Barcode, 13 Barcode, EAN Barcode, etc..)
Barcode card is simple, ordinary bar code printing or copying can be in accordance with certain requirements, low cost, but the reader device(especially the QR code reading apparatus) more expensive. Comparing to the magnetic card and IC card, barcode card information cannot be changed. In addition, security of energy difference, the standard is not uniform. All of these limit the its application.