Choose your model of Android:
Android is a Linux-based, open source operating system for mobile devices created by Android Inc., now owned by Google. Today, many different companies use Android for their mobile device product lines including Samsung, HTC, Motorola, and many others.
The first Android phone was the HTC Dream released in October of 2008. Since then Android devices, including tablets and phones, have become popular all across the world. As of May 2013, a total of 900 million Android devices had been activated and 48 billion apps had been installed from the Google Play store. It's currently the most widely used smartphone OS.