The Kindle Fire is a family of Android-based devices, using the Amazon ecosystem and running their AppStore for third party applications instead of the Google Play Store.
Amazon introduced the Kindle Fire on November 15, 2011. Based on the Android operating system, the original 7" color tablet device was tightly coupled with Amazon's Kindle ebook library, App Store, memberships (Prime) and web services (as a caching proxy for the Silk web browser).
In 2012 they released an Android 4.0.2 based update to the original 7" device, as well as a new HD 7" and 8.9" devices and with more emphasis on the android app eco-system.
In 2013 they released Android 4.2 based 7" HD and HDX devices and an 8.9" HDX model.
In April 2014, a smart TV device, building on the Kindle Fire brand and similarly using Android, called Amazon Fire TV was introduced.
In September 2014, they announced FireOS4 (Android 4.4) based 6", 7" HD devices and an updated 8.9" HDX, as well as beginning a roll-out of FireOS4 to the 2013 HDX tablets.