Hard disk
From Simple English Wikipedia, the free encyclopedia
A hard disk or hard disk drive (sometimes 'disk' is also spelled disc) or hard drive, is something used by computers to store information. Hard disks use magnets to store information. A hard disk is sometimes known by its acronym, HD, or HDD.
There are several different types of interface when dealing with hard drives. The most common (at the moment) is the IDE interface (a.k.a eIDE or ATA/133), which is found on most home desktop PC's. This interface has been around for a number of years, and though not the fastest, is the most widely used and (usually) the lowest priced. In recent years, the SATA interface has become more popular within the home PC market. This interface allows for faster data transfer rates and comes in several sub-categories, each with its own speed and protocols. SATA drives are usually marginally more expensive for the domestic consumer. For high-end applications (i.e. servers within businesses), the SCSI (pronounced 'scuzzy')interface is very popular. Again, there are several types of SCSI interface, each stepping-up in terms of speed and price. Within servers, several SCSI drives are often used in conjunction with each other, in order to safeguard against data loss or corruption (this is known as RAID - and there are many different configurations to choose from).
In addition to the above interfaces, Fibre Channel drives are now becoming more popular at the higher end of the market, however for your average domestic computer user, the choice for the moment lies between IDE and SATA.