Fire OS is an operating system that runs Amazon devices, such as the Kindle Fire, Fire Phone, Amazon Echo devices, and the Fire TV Stick. It is a modified version of the Android operating system. The first version of Fire OS was based on the Android 2.3 Gingerbread operating system. As of January 2019, Fire OS 5 is the latest version available and is based on Android Lollipop.
Amazon attempted to license Fire OS as its own operating system and include it on new Amazon smartphones, called the Fire Phone, but Google blocked Amazon through its license agreement.
Differences between Fire OS and Android
While being based on the Android operating system, Fire OS has multiple differences. Unlike Android which uses the Chrome browser, Fire OS uses the Silk browser. Also, Amazon includes its own store app, the Amazon Appstore, in Fire OS instead of the Google Play app on the Android OS. Amazon also included its own cloud drive and cloud player apps, instead of using Google Drive.