FAT (File Allocation Table) : 12 or 16 bit, with a maximum volume size of 2 Gb. It can have 255 characters in file name in Windows 9x/200/NT4 plus.

FDISK command does partition on hard disk. FDISK can create or remove partitions. Partitioning may cause loss of data. Partition Magic software partitions the disk without loss of data. FAT 32 uses 32 bit to identify the clusters, thus can have a maximum volume size of 2048 Gb. Recommended number of partitions in a disk is 2.

After the partition, the operating system does a high level formatting of HD. Format command does high level formatting in a HD, while low level formatting and high level formatting in a floppy disk.

A motor can become a generator and vice versa. During recording on a HD, the head changes electrical impulses to magnetic fields, and while reading the head changes the magnetic field back into electrical impulses. Heads are electromagnets whose voltage can be switched in polarity very quickly.