If you see picture like the one below, it not called a bar code but called a QR code. Actually QR code used for Android phone as a shortcut to get link to content online or install android application using your phone camera. With this way, you can saving your time from typing lengthy addresses into your mobile browser.
A QR Code is a specific matrix barcode (or two-dimensional code), readable by dedicated QR barcode readers and camera phones. The code consists of black modules arranged in a square pattern on a white background. The information encoded can be text, URL or other data.
How to use your QR codes with your Android phone
For Android user, you can install barcode scanner or barcode reader app from android market. Once you install barcode scanner app on your Android phone, run barcode scanner and point your camera at a QR code. It will show you to the download section in the Android Market. For example, can try scan this QR code above using your android smartphone.
