Landing zone
A data-free band at the inner edge of the platter where the heads settle at power-down so they never rest on data.
When a hard disk spins down, the heads lose their air cushion and sink toward the surface. If they land on a data track they can scratch it; so they are first moved into an empty zone meant only to receive them. Older disks needed manual parking — the DOS PARK command — before moving the machine, while later drives auto-parked on power loss.
Contact start-stop drives textured or lubricated the landing zone so it could survive thousands of starts and stops without a head crash. Modern drives instead lift the heads off entirely onto a ramp beside the platter (ramp load/unload) and need no landing zone on the surface at all.