1st Hard Disk Drive
The option description:
Gives the chance to specify a hard disk on which it is necessary to search for an operating system: it can be a disk connected to the standard IDE-/SATA-controler of a chipset, or a disk connected to additional SCSI – or to the RAID-controler. The option is actual, when in system is installed more than one hard disk.
In most cases at a choice of this option (pushing it of a key [<Enter>]) you get to the additional menu where it is already possible to select the order of inquiry of hard disks immediately.
Other options identical to destination: