Android Operating System

Android is a software platform and operating system for mobile devices, based on the Linux kernel, and developed by Google and later the Open Handset Alliance. It allows developers to write managed code in the Java language, controlling the device via Googledeveloped Java libraries. Android is available as open source. Android is a freely downloadable open source software stack for mobile devices that includes an operating system, middleware and key applications based on Linux and Java. Google purchased the developer of Android in 2005, and Android was unveiled in 2007. Google released the Android code as open-source under the Apache License. Android has numerous developers writing applications (apps) all over the world. First of all the developers write their script in Java, and then download the apps from the third party sites or online stores.

In February 2012, 450,000 apps were available for Android but the estimated number of downloads since December, 2011 was more than 10 billion. There are over 300 million Androids in use and over 850,000 devices activated every day. Android is the one of the most used mobile operating system with a market share of 48% and Over 400,000 applications available in Google play store. Android apps have been installed over 10 billion times and cover a vast range of categories from games and entertainment to financial and business services. Android software development and the Google Play Market are relatively open and unrestricted. This offers both developers and users more flexibility and freedom, but also creates significant security challenges.

Android Versions

Major improvements in each release involve:

• Cupcake – UI (User Interface) refinement updates of all core elements, accelerometerbased application rotations, on-screen soft keyboard, video recording and playback, stereo Bluetooth support;
• Donut – quick search box, VPN (Virtual Private Network) and 802.1x support, battery usage indicator;
• Éclair – Bluetooth 2.1 support, additional camera modes, multiple e-mail and account support;
• Froyo – tethering and WiFi hotspot capability, JIT (Just In Time) compiler, Adobe Flash support;
• Gingerbread – NFC (Near Field Communications), additional sensor support (gyroscope, rotation vector, linear acceleration, gravity, barometer), multiple camera support, large screen resolution support (tablets), Google Talk;
• Honeycomb – tablet-only android update, connectivity for USB (Universal Serial Bus) accessories, high-performance WiFi lock;
• Ice Cream Sandwich – WiFi Direct, Face Unlock, numerous improvements (stability, optimization, screen rotation, graphics);
• Jelly Bean – Google Wallet, Google Now, USB audio, Photo Sphere panorama photos, multiple user accounts, Miracast wireless display support;
• KitKat – NFC host card emulation, new experimental runtime virtual machine (ART), Bluetooth MAP (Message Access Profile) support;
• Lollipop – Dalvik replaced with ART with AOT (Ahead-Of-Time) compilation, support for 64-bit CPUs, OpenGL ES 3.1 support, recent activities screen with tasks instead of applications, project Volta (battery life improvements), audio input and output through USB devices.