Qi is a global standard that makes wireless charging possible for your device. With a Qi-compatible device, you don't need to connect any cables. You just place your device on the charging surface.
Qi works using magnetic induction, and is currently designed for devices that use 5 watts of power or less, such as mobile phones. Qi chargers and devices use the same frequency, so as long as their active areas are touching, all Qi products are compatible, regardless of manufacturer or brand. For more details, see the user guides of both devices.