What is Android?
Android is an open-source operating system based on Linux with a Java programming interface for mobile devices such as Smartphone (Touch Screen Devices who supports Android OS) as well for Tablets too.
Android was developed by the Open Handset Alliance (OHA), which is led by Google. The Open Handset Alliance (OHA) is a consortium of multiple companies like Samsung, Sony, Intel and many more to provide services and deploy handsets using the android platform.
In 2007, Google released a first beta version of the Android Software Development Kit (SDK) and the first commercial version of Android 1.0 (with name Alpha), was released in September 2008.
In 2012, Google released another version of android, 4.1 Jelly Bean. It’s an incremental update and it improved a lot in terms of the user interface, functionality, and performance.
In 2014, Google announced another Latest Version, 5.0 Lollipop. In Lollipop version Google completely revamped the UI by using Material Designs, which is good for the User Interface as well for the themes related.
All the source code for Android is available free on Git-Hub, Stack overflow, and many more websites. Google publishes most of the code under the Apache License version 2.0.