https://arstechnica.com/gadgets/2017/09/how-qi-wireless-charging-works-and-why-it-hasnt-taken-over-yet/

The Qi wireless charging standard from the Wireless Power Consortium (WPC) is having a relatively good year. Now is a good time for a bird’s-eye view of the technology—how it works, what it’s for, and what its prospects are. This is also a good time because millions of Apple ecosystem users are about to get their first sampling of Qi when the iPhone 8 and iPhone 8 Plus launch this Friday.

Qi has appeared in phones of various stripes for more than five years, and many people are already using it. The basic tech has been used for consumer products like razors and toothbrushes for a while, plus a variety of non-consumer tools.