Hard Disk Drive

 Hard drive is a non-volatile memory hardware which store all your computer’s information and data physically in it and houses the hard disk. Sometimes hard disk is also known by the terms Hard Disk Drive.

A Hard Disk Drive has a magnetic material coated plates where the information to be recorded. In contrast to sequentially addressable storage media such as magnetic tape or punched tape drives, Hard Disk Drive is a direct access storage device or DASD, as data can be accessed directly from a Hard Disk Drive.

Structure  of Hard Disk Drive

Common form factors for Hard Disk Drive (the width) is 5.25 “, 3.5”, 2.5 “and 1.8” . Upto 0.85 inch Hard Disk Drive is available but usually 3.5 inch hard drive is the standard in desktop computers. A hard disk consists of one or more rotating mounted disks, one axis, also called spindle, an electric motor to rotate the disks, moving heads which read and writes the data, an IC for for controlling the motor and head, a dedicated RAM, outer very strong casing and the interfaces to attach for power supply and data exchange.

Function Of Hard Drive

The main function of hard disk is to store data for long term and data can be computer’s operating systems, applications, documents, personal files and so on. Now the main thing that need to notice that how much amount of data storage capacity hard drive have and that measured in gigabytes or terabytes. Performance refers to read and write speeds, latency, seek time. Seek and latency time measured in the time that are going to take magnetic heads in hard disk to access the data desired and the read write speed and data transfer rate are measured that how much capacity data can be written from the drive and read from a desired location in specific amount of time.