Term: partition

A partition is a division of the area on a physical hard disk (or disk-like device) into one or more logical disks.

In many systems and on many disks, the two are effectively synonymous: a single partition is constructed that encompasses the entire available space on on a hard disk.

Dividing a hard disk into multiple partitions is simply a method of organizing the available physical space. A single 1TB drive, for example, could be divided into two partitions of roughly 500GB each (ignoring overhead). Once formatted, these two divisions could be mounted as two separate volumes (perhaps C: and D: in Windows), when in fact there is only one physical drive.

Partitioning is commonly used by computer manufacturers to place data, such as a pristine system image or other installation media, onto a hard disk when an operating system is pre-installed. A small partition – typically hidden, so as not to be visible by default – is created to contain this recovery information, and the remainder of the disk is set up as a separate, visible, partition.