Aside from backup, recovery, and damage limitation, there are administrative functions that may differ depending on how a disk is partitioned. In particular, using a single partition for an entire disk relieves an administrator from having to modify partition sizes if one partition fills up and more space is necessary. TIlls is frequently why a single disk partition (plus swap space) is the recommendation for new users who are uncertain how they want to partition their drives.
Early BIOS systems could not boot from locations beyond the first 1024 cylinders of the disk. Thus, at one time, it was necessary to create a small/boot partition below that limit so that the system code (which could access larger areas) could be booted.
