Wireless charging works using transmitter coils (charger) and receptor coils (in your mobile device). It is achieved thanks to Qi technology, which works by induction. Instead of traditional cables to provide power and charge to the device, wireless charging transmits power via electromagnetic fields.
The transmitter coils generate a magnetic field that attracts the receptor coils, generating electrical voltage that charges the device without the need for physical cables between the two devices. This process is referred to as electromagnetic induction or inductive charging.
Qi technology is an inductive charging standard that allows the charging of smart devices without the need to connect them via a cable. The Wireless Power Consortium (WPC) is the body charges with promoting Qi wireless charging technology.
The Qi certificate is a product conformity label issued by the Wireless Power Consortium, the highest certification body for this technology, that only approves and certifies those products that have been tested and approved as being developed in accordance with the demanding specifications for this technology.
In recent years, Qi wireless charging has been integrated into the majority of smartphones from leading brands (including Apple and Samsung). Virtually all smartphones developed in the last 5 years support wireless charging, although there are some that do not.