The operating system operates on mobile devices like phones, tablets, smartwatches, or other mobile devices is called a mobile operating system. An overview of different mobile operating systems that are currently available in the market is shown in Fig.

Reference: netmarketshare(dot)com

The above graph shows two main mobile operating systems, Android, iOS, and rest comprises of Windows Mobile and Symbian OS, etc. Android has captured most of the market.

Mobile OS: Android

Android is an open source operating system for mobile devices developed by Google and the Open Handset Alliance. With close to 70% market share. The system architecture consists of :

• A modified Linux Kernel
• Open source Libraries coded in C and C++
• The Android Run-time, which considers core libraries that disposes of the most core functions of Java. Like a virtual machine, it uses Dalvin, which enables to execute Java applications.
• An Application Framework, which disposes of services and libraries coded in Java for the application development
• The Applications, which operate on it

Android is mostly made up of a Linux kernel and Java. This combination gives some secure features, like efficient shared memory management, preemptive multitasking, Unix user identifiers (UIDs) and file permissions with the type-safe concept of Java. Every Android application runs in a separate process. It has a unique UID with distinct permissions, which means that applications can typically not read or write each other’s data or code.

The Android mobile operating system is Google's open and free software like a stack that contains an operating system, middleware and also key applications for use on mobile devices, including smartphones. Updates for the open source Android mobile operating system have been developed under "dessert-inspired" version names (Cupcake, Donut, Eclair, Froyo, Gingerbread, Honeycomb, Ice Cream Sandwich, Jelly bean, KitKat, etc.) with each new version arriving in alphabetical order with new enhancements and improvements.