A hard disk is a secondary data storage device which is placed in the system. It is just similar to the human brain, where all the past and present events are kept. It is made up of a magnetic material which stores the data by the magnetic recording techniques.
Type of Hard Disk
Depending upon how it is connected to the system, Hard disks are of two types
Ø Internal Hard disk Drive
Ø External Hard Disk drive
Internal Hard disk Drive
Internal Hard disks drives are connected inside the system using IDE/SATA connectors available on the motherboard.
External Hard Disk drive
An external Hard disk drive is a portable storage device which is externally connected to a computer using a high-speed cable. The cables which are used to connect a computer must be compatible with IDE, SCSI, eSATA, and USB. The most common used cables are USB, SATA, and Firewire.
The different hard disk specifies the speed at which the hard disk transfers data and the reliability of the hard disk in terms of storing data. The different types of hard disk drives are
Ø IDE/PATA Drives
Ø Serial (SATA) Drives
IDE/PATA Drives (Integrated Drive Electronics)
These drives are also called PATA (Parallel Advanced Technology Attachment) as it uses parallel communication. The PATA drives wire transfer data between the hard disk and system using 16 bits bus width speed upto133 MB per second.
SATA (Serial ATA) Hard Disk Drives
Serial ATA uses serial communication i.e. transfer data 1 bit at a time with the speed of up to 600 MBPS.SATA hard disk uses a smaller 7-wire cable to connect to the system. This cable can have the maximum length of 1 meter.
SATA offers the following advantages over IDE technology
Ø Point to point connection topology ensures dedicated 600 MBPS to each device.
Ø Thinner, Longer Cables for easier routing.
Ø Fewer interference signals require less board space and allow for simpler routing.
Ø Better connector design for easier installation and better device reliability.
Ø Hot-swap capability