MIUI is an Android-based operating system for smartphones and tablet computers developed by Chinese electronics manufacturer Xiaomi. This is a fork of the Android OS. MIUI includes various features such as theme support.
Xiaomi has released some smartphones with Android One while others have MIUI, based on the current version of Android. Xiaomi devices usually get one Android version update, but get MIUI updates for four years.
The first MIUI ROM was based on Android 2.2.x Froyo and was initially developed in the Chinese language by Chinese startup Xiaomi Tech. Xiaomi added a number of apps to the basic framework, including their Notes, Backup, Music, and Gallery apps.