Introduction of Android

Android is a mobile operating system. Initially android developed by Android, Inc.later Google purchased in 2005, Android OS is open source .So developer can easily develop the application according to their needs without any restrictions.The very first Android powered phone was sold in Oct 2008.
Android has a large number of developers writing android applications that extend the functionality of devices, written primarily in java programming language. Any one know the core java can easily make android application.