My most familiar operating system is Android.

Android is a free and open source operating system based on Linux. Mainly used in mobile devices, such as smartphones and tablets, led and developed by Google and the Open Mobile Alliance. The Android operating system was originally developed by Andy Rubin, which mainly supports mobile phones. In August 2005, Google acquired the capital injection. In November 2007, Google formed an open mobile alliance with 84 hardware manufacturers, software developers and telecom operators to develop and improve Android systems. Then Google released Android's source code in the form of an Apache open source license. The first Android smartphone was released in October 2008. Android has gradually expanded to tablets and other areas, such as television, digital cameras, game consoles, smart watches and so on.