Working Of Hard Disk

Disks are rotated continuously so that read/write heads mounted on movable or fixed arms can read or write programs or data to and from the disk. The Hard Disk Drive can be classified into two sections mechanical section and electronic section. The mechanical section  consists of the following which are explained accordingly.

Spindle Motor  :  One part of a hard disk, around which the platters rotate.

Disk drive : The motor that actually rotates the disk, plus the read/write heads and associated mechanisms, usually in a mountable housing. Sometimes, it is used synonymously to mean the entire disk subsystem

platters : The platters are no. of disks made of aluminum or plastic coated with a magnetic material. The data is stored on the platter.

Read/write Head : The part of the hard disk which writes data to or reads data from a platter it functions like a coiled wire that reacts to a changing magnetic field by producing a minute current that can be detected and amplified by the electronics of the disk drive.

Head Actuator : In a disk drive, the mechanism which moves the read/write head radially across the surface of the platter of the disk drive.

Electronic Section of HDD : The electronic section consists of a logic card which controls the stepper and the spindle motors and the read/write heads of the disk it has 40 pin IDE interface data cable connector and a 4 pin D-type power supply connector.

Sector : The basic storage unit on a hard disk, On most modern hard disks, sectors are 512 bytes each, four sectors make up a cluster, and there are 17 to 34 sectors in a track although newer drives may have a different number of sctors.
Track : The cicular path traced across the spinning surface of a disk platter by the read write head inside the hard-disk drive. The track consists of one or more clusters.