sentences:  Track0 is also increasingly used to store licensing information for particular pieces of software because it is an area of the disk outside of the OS filesystem and not seen or used by most computer users (and therefore cannot be easily modified or replicated).The origins of Track0 came about from the original specifications of PCs, where computer hard disks were defined in terms of Cylinders, Heads and Sectors (CHS system).In this context, Track0 was defined to be all the sectors on the first cylinder and first head.