Fdisk Utility is used to manage partitions on hard disk devices. Under linux all kind of devices are located under /dev/ directory.
Types of Disks
IDE drives will be given device names /dev/hda to /dev/hdd.
SCSI drives will be given device names /dev/sda to /dev/sdd.
The RAW Devices allocated from a Linux Storage Server can be anything, depending on what the IT pepole assign to a Linux machine.
Types of Partitions
A partition is a logically independent division on a HDD. An entire operating system can be installed there.
One primary partition of a hard drive may be subpartitioned. These are logical partitions. The primary partition used to house the logical partitions is called an '''extended partition''' and it has its own file system type (0x05). Unlike primary partitions, logical partitions must be contiguous.
Every process running on your computer is allocated a number of blocks of RAM. These blocks are called pages. If you have too many processes running on a machine, the kernel will try to free up RAM by writing pages to disk. This is what swap space is for. It effectively increases the amount of memory you have available.