What is primary partition and extended partition?
A primary partition is one that can be used as system partition. Windows and
other operating systems can start from a primary partition. You can create
maximum four primary partitions on a hard disk. Primary partitions can be
created only on hard disk and cannot be sub partitioned.
A type of disk partition that can further be divided into sub-partitions is
called extended partition. In this way, a number of logical hard disk drives can
be created. Each logical disk drive is assigned a unique letter such as C, D, E,
and so on. In Windows, maximum four primary partitions can be created on hard disk. However, a hard disk can have only one extended partition.