Want Info about Wireless Charging

In today's era, as technology is evolved & moving up & up. Yesterday I am talking to my friend & I heard about Wireless charging. But i am quite confused that how charging can be possible without wires, I mean if we supply energy from one gadget to another at minimum range then there must be loss of energy ?

Or what happen if we put any other gadget between the supplier & the receiver ?

If anyone have any idea about my questions, please answer it.