Quick Response Codes are 2-dimensional barcodes, which can be used for many things. Data are encoded into a graphical format which then can be read by a camera and evaluated using special apps (barcode readers). Example usages include linking to web pages or exchanging contact data. See the 'info' link for further details.
Quoting the Wikipedia article on "QR Code":
QR code (abbreviated from Quick Response Code) is the trademark for a type of matrix barcode (or two-dimensional bar code) first designed for the automotive industry in Japan. Bar codes are optical machine-readable labels attached to items that record information related to the item. [...] Recently, the QR Code system has become popular outside the automotive industry due to its fast readability and greater storage capacity compared to standard UPC barcodes. The code consists of black modules (square dots) arranged in a square grid on a white background. The information encoded may be made up of four standardized types ("modes") of data (numeric, alphanumeric, byte / binary, Kanji) or, through supported extensions, virtually any type of data.
QR code for the URL of the English Wikipedia Mobile main page, "http://en.m.wikipedia.org"
Related to our Android devices, a few example usages include:
- Linking to web pages from printed media
- Sharing your contact data in an easy way
- Providing a quick way to pick access data for your WiFi router by your friends/visitors
- Sharing appointments (calendar data)