The next most popular hard disk interface used today is the Small Computer Systems Interface(SCSI) which is a much more advanced interface compared to its main competitor IDE / ATA as it has several advantages over IDE that makes it the most preferred at many situations, mostly in higher-end machines. However, it is less commonly used than IDE / ATA, the reason being its higher cost and also because of the fact that its advantages are not useful for the typical home or business desktop user.
SCSI is a much higher-level protocol than IDE is. Basically,
While IDE is an interface, SCSI is really a system-level bus, with intelligent controllers on each SCSI device that work together and manages the flow of information on the channel. It supports many different types of devices.
While IDE is a controller, SCSI is a separate bus, which is fitted on to the system bus via a host adapter.
A single SCSI bus can hold up to 8 units that have a different SCSI ID in the range of 0 to 7.
The host adapter takes one of the Ids, while the balance seven ID's are left for the other hardware.
Usually SCSI hardware is comprised of hard disks, tape drives, CD-R/RW drives, and scanners to name a few.
