Final answer:
An extended partition is unique to the MBR partitioning scheme and allows for the creation of additional logical partitions within a hard disk that has an MBR, exceeding the limit of four primary partitions.
Step-by-step explanation:
The term that describes a type of partition that would only exist on a hard disk with a Master Boot Record (MBR) is an extended partition. An extended partition is unique to the MBR partitioning scheme and allows for the creation of a container within which multiple logical partitions can be created. This is necessary because MBR itself limits the number of partitions to four. To bypass this limit, one or more of these four partitions can be made an extended partition, with logical partitions within it. This differs from a primary partition, which is directly bootable, and a system partition, which contains the bootloader and operating system files.