This brings up a question: How does wireless charging work? Among the engineers and scientists, wireless charging is known as 'inductive charging'. It utilizes two smart coils - one in the charger and another in the device that is getting charged. The primary coil creates a very small electromagnetic field around the charger through which electricity can be transferred. The secondary coil, which is in the phone, receives the power from electromagnetic field and converts in back into electric current to feed it into the battery.
The technology is still in the early stages and it works best when the distance between the two coils is few millimeters. That's the reason why users have to place the device on the charger.
The main benefit of wireless charging is that it removes one more wire. This not only makes it easier to charge the phone but also has aesthetic appeal. At the same time, wireless charging has poor efficiency. This means it takes longer to charge the battery through wireless charger.
Galaxy S3 is not the first phone to use wireless charging. Three years ago Palm commercialized the technology and sold a charger called Touchstone that allowed phones like Pre and Pixi to be charged wirelessly. Powermat is another company that sells special chargers, which can be used with iPhone and other devices for wireless charging.
After introducing the technology in 2009, Palm supported it in almost all of its devices. Even Touchpad, which was introduced in the market last year after Palm had been acquired by HP, had this feature. Of course, Palm is dead now.