"As we've stated, the Xbox One controller, although it looks similar in many ways, shares no underlying technology with the current Xbox 360 controller. New wireless protocol, combined with the ability to work in 'wired' mode, and the addition of features like Impulse triggers, means that new software has to be written and optimized for the PC," the representative told CVG . The representative also said work must go into ensuring existing games supporting Xbox 360 controllers also support the Xbox One game pad.
One of the big differentiators between the Xbox One and Xbox 360 controllers is Wired mode, which allows an Xbox One game pad, when plugged in through micro-USB, to disable its radios and operate as a true wired controller.
Microsoft Xbox One