Passage: MI User Interface, abbreviated MIUI (pronunciation: Me You I), is a stock and aftermarket firmware for smartphones and tablet computers developed by Chinese electronics manufacturer Xiaomi. The firmware is based on Google's Android operating system. MIUI includes various features such as theme support.Xiaomi has released various smartphones, all but Mi A1, Mi A2 and Mi A2 lite of which come pre-installed with a complete version of MIUI. Xiaomi devices usually get one Android version update, but get MIUI updates for four years. This has made various apps and features not available in the aftermarket version of MIUI, but available only through rooting.

Question: What has various features?
MIUI