When looking at menus in restaurants, listening to instructions in museums, and until we get on the bus, we use QR codes every day. You can check the information you want right away with your smartphone  by shining a few seconds on it. So how is there a lot of information in the small black and white squares?

   QR codes store information by converting it into zeros and ones (binary digits), which are languages that computers understand. The converted zeros and ones are expressed as small black and white squares (modules). When smartphone cameras read the arrangement of the squares, they are converted back into original information such as letters, numbers, and Internet addresses (URL).

   The biggest feature of QR codes is the three large squares on the corners. This is called the "location pattern," and it helps cameras quickly find the direction and location of QR codes. In addition, QR codes contain error correction technology, which can restore the original information even if some of them are torn or covered.

   QR codes have the advantage of being able to store much more information than regular barcodes. This is because barcodes contain information only in one-line direction, but QR codes use both horizontal and vertical directions. It can also be quickly recognized, store a lot of information even in a small space, and is highly likely to read even if damaged. Therefore, it is used in various fields such as payment, access authentication, logistics management, electronic entry and exit lists, and tourism information.

QR codes are expected to become smarter in the future. Combined with artificial intelligence (AI), security functions that can provide personal information or prevent forgery can be further enhanced. In addition, technology that is connected to augmented reality (AR) and displays a 3D guide screen or image when a QR code is projected is being developed. It is expected that the era of using QR codes will open in various places such as buildings, clothes, and products as well as paper.

Amazing science and technology are hidden in QR codes that look like simple patterns of small squares. In the future, QR codes will continue to develop into important technologies that make our lives more convenient and safe.