TYPES OF DESKTOP HARD DRIVES

ATA/IDE
Introduced in 1986, this is the standard 16 bit parallel interface called ATA- commonly referred to as IDE (Integrated Drive Electronics).  It refers to a drive with a built-in controller which greatly simplifies installation into the computer.  It supports transfer of data up to 133MB per second.  Most desktop and laptop computers use the standard IDE interface. 

SATA
Introduced in the year 2000, SATA was designed as an improvement over the ATA interface.  It is a 1 bit serial interface
that currently supports data transfer at a rate of 300 MB per second.  SATA also includes other benefits over ATA including
improved wiring, improved reliability, cyclic redundancy checking to protect data, and hot plug capability.

SCSI
The SCSI (Small Computer System Interface) is a shared bus interface.  Using SCSI, data is transferred between devices on both internal and external computer buses.  The current SCSI standard using a narrow bus configuration allows for up to 8 devices to be connected. Using a wide bus configuration, up to 16 devices can be connected.  Since SCSI was designed
for performance, it is commonly used in RAID, workstations, and servers. It can also be used in devices such as printers
and scanners. 

Serial Attached SCSI (SAS)
SAS is a serial communication protocol allowing for higher speed data transfer.  It is commonly being used in the corporate
environment.  Serial Attached SCSI offers data transfer rates ranging from 3 Gbps to 10 Gbps.  In addition, SAS devices are compatible with SATA devices.