https://www.cnbc.com/2017/09/12/iphone-wireless-charging-dock-not-ready-to-launch-says-kgi.html

The three new iPhones that Apple is expected to launch on Tuesday reportedly support wireless charging, but the company's first-party wireless charger isn't ready, according to KGI Securities.

Wireless charging will allow you to drop the iPhone on a pad to charge, instead of having to plug it in. Android phones have offered the function for some time. The new iPhones are supposed to be Apple's first to feature the option.