Hard+disk+drive

Hard drive is a magnetic disk and the largest data storage in a computer, it can store anywhere from 8 to 4000 (4TB) gigabytes. All software and files in a computer are stored in the hard drive.The hard disk in a computer can be removed and used by other computers. (Desktop computers are typically 3.5inch HDD's and Laptop's are 2.5inch HDD's)

A hard disk is made up by many platters inside; each platter requires two read/write head, one for each side. To make sure that these platters can’t move independently, all the read write head are attached to a single access arm. Each platter has the same amount of tracks, and a tracks location that cut across all platters is called a cylinder. The disk in the hard disk can spin at up to 10,000 revolutions per minute.

The hard drive also has two motors, the stepper motor and the spindle motor. The stepper motor powers the read/write head and the spindle motor powers the the spindle (which in turn spins the disk).