Android is an operating system for mobile devices such as smartphones and tablet computers. It consists of a kernel based on the Linux kernel, with middleware, libraries and APIs written in C and application software running on an application framework which includes Java-compatible libraries based on Apache Harmony.
Android has a large community of developers writing applications ("apps") that extend the functionality of the devices. Developers write primarily in a customized version of Java.
Apps can be downloaded from third-party sites or through online stores such as Google Play Store , the app store run by Google.