An image like this is called a “QR code”. It represents the web address (URL) of a single HTML page. The image shown on the left stands for “www.ecb.europa.eu”.
A QR code enables you to bookmark an ECB web page with your mobile phone quickly and easily. Our URLs can get very long: “www.ecb.europa.eu/paym/sepa/benefits/consumers/html/index.en.html” is one example. But with a QR code there is no need to type the full URL into your phone, instead you simply scan the image. Your phone reads it, converts it back into the URL and stores it as a bookmark. Then you can use your phone to go online to that page.
There may not be a QR code reader for some models of mobile phones.
We suggest you try these two websites, although others may offer a similar service
reader.kaywa.com
www.quickmark.com.tw
For more details, see the Wikipedia article on QR code.