Bar codes have become widely popular because of their reading speed, accuracy, and superior functionality characteristics.

As bar codes became popular and their convenience universally recognized, the market began to call for codes capable of storing more information, more character types, and that could be printed in a smaller space.

As a result, various efforts were made to increase the amount of information stored by bar codes, such as increasing the number of bar code digits or layout multiple bar codes.

However, these improvements also caused problems such as enlarging the bar code area, complicating reading operations, and increasing printing cost.

2D Code emerged in response to these needs and problems

2D Code is also progressing from the stacked bar code method (that stacks bar codes), to the increased information density matrix method.

QR Code is a kind of 2-D (two-dimensional) symbology developed by Denso Wave (a division of Denso Corporation at the time) and released in 1994 with the primary aim of being a symbol that is easily interpreted by scanner equipment.

QR Code (2D Code) contains information in both the vertical and horizontal directions, whereas a bar code contains data in one direction only. QR Code holds a considerably greater volume of information than a bar code.

In addition to QR Code, some other kinds of 2D Code have been developed. Below is a table of typical 2D Code and their features.