Android is an operating system for mobiles. Android operating system is developed by Google. Android is based on the Linux Kernel i.e. the main core of the code written for android is based on the Linux main core code.
Android operating system is designed for the smartphones and tablets that has touchscreen functionality. Android is the best selling operating system for tablets since 2013. Android was initially developed by Android Inc. which was taken over by Google in 2005. Android was released by Google in 2007 by the name Android alpha. In 2009 it was upgraded to Android 1.5 i.e. Android cupcake.
Here is a complete list of Android versions along with their release date –
Android 1.0 - September 23, 2008
Android 1.1 - February 9, 2009
Android Cupcake (ver. 1.5) - April 27, 2009
Android Donut (ver. 1.6) - September 15, 2009
Android Eclair (ver. 2.0 - 2.1) - October 26, 2009
Android Froyo (ver. 2.2 – 2.2.3) - May 20, 2010
Android Gingerbread (ver. 2.3 – 2.3.7) - December 6, 2010
Android Honeycomb (ver. 3.0 – 3.2.6) - February 22, 2011
Android Ice Cream Sandwich (ver. 4.0 – 4.0.4) - October 18, 2011
Android Jelly Bean (ver. 4.1 – 4.3.1) - July 9, 2012
Android KitKat (ver. 4.4 – 4.4.4) - October 31, 2013
Android Lollipop (ver. 5.0 – 5.1.1) - November 12, 2014
Android Marshmallow (ver. 6.0 – 6.0.1) - October 5, 2015
Android Nougat (ver. 7.0 – 7.1.1) - August 22, 2016
At the time of writing Android Nougat is the current Android Version. Android Marshmallow and Android Nougat are the two which are still supported by Google.
Apart from handheld devices Google has expanded the span of Android to Android TV for televisions, Android auto for cars, Android wear for wrist watches, cameras, notebooks, gaming consoles etc.
Mobile apps are being continuously developed for Android by developers all over the world. Google play store has millions of Android apps already downloaded. Android is a popular operating system among the developers as it itself is open source and hence can be used to develop large projects using the source code of the base operating system.