|HPA (HPA Host Protected Area)|
The host protected area is a part of the hard disk which is not addressable by the user and operating system. HPA is typically used by the BIOS for standby/sleep support. In that case the hard disk section allows the memory to be dumped to it. After a HPA section has been set the drive simulates a drive of the total size minus the HPA reserved area making the HPA inaccessible to others.