Steel that has been taken from Satan's throne itself and melted down in the pits of the underworld. (and then moulded and assembled by some fine China-man for 3 pence an hour)
Basically it's like the difference between a fender and a squier but in tremelo form....or between Asian and U.S. made.
Original Floyd Rose is made by Floyd Rose, licensed means the design patent is licensed to other companies to copy it.