Wireless charging is a technology that allows charging over (very) short distances without cables.
The advantage of wireless charging is that it’s quicker and easier, as you don’t have to plug and unplug each time.. you just place your device on top of your wireless charging pad.

TECHNICAL INFO

It works like this: A magnetic loop antenna (copper coil) is used to create an oscillating magnetic field, which can create a current in one or more receiver antennas. If the appropriate capacitance is added so that the loops resonate at the same frequency, the amount of induced current in the receivers increases. This is resonant inductive charging or magnetic resonance; it enables power transmission at greater distances between transmitter and receiver and increases efficiency. Coil size also affects the distance of power transfer. The bigger the coil, or the more coils there are, the greater the distance a charge can travel. 

In the case of smartphone wireless charging pads, for example, the copper coils are only a few inches in diameter, severely limiting the distance over which power can travel efficiently. But when the coils are larger, more energy can be transferred wirelessly.

Check HERE if your smartphone charge wirelessly.