This document provides an overview of the Android operating system. It discusses Android as the most advanced mobile OS, lists the trending mobile OSes, and describes the history and versions of Android. Key features of Android like its use of Linux kernel, Dalvik virtual machine, connectivity options, and hardware support are explained. Comparisons are made between Android and other mobile OSes like Symbian, iOS, Windows Phone in terms of usage statistics, development processes, and reasons for their advantages. The future possibilities of Android becoming the dominant mobile OS are also outlined.