Data storage systems are devices capable of storing data. The term usually refers to mass storage devices, such as hard drives, tape drives, floppy drives, removable cartridge hard disk drives, CD-ROM drives, and DVD-ROM drives.

The hard drive in a computer is also called the hard disk, hard disk drive or fixed disk drive. Most computers have one hard drive located inside the computer case.  If a computer has one hard drive, it is usually called drive C.  If a computer has additional hard drives, they are called drives D, E, F, etc.  The amount of information a hard drive can store is measured in bytes. 

Important specifications to consider when searching for data storage systems include capacity and transfer rate.  Capacity is the amount of space available to store data.  Transfer rate is the speed at which bits of data are sent. For example, this could describe the rate at which the bits of information are read from the disk and sent to the drive's controller (internal rate), or characterize data exchange between the controller and PC's CPU (external rate).  Dimensions of width, length, and height are also important to consider.  Common interfaces for data storage devices include Fibre Channel, IEEE 1394, IDE, SCSI, and USB.  Choices for mounting include chassis mount, free standing, integrally mounted, panel mount, and rack mount.  An important environmental parameter to consider when searching for data storage devices includes the operating temperature. 

Hard Drives Specifications

SATA Interface
Serial ATA (SATA) hard drives are quickly becoming the new standard in hard drive technology. Motherboard manufacturers now include SATA inputs on their boards. SATA hard drives result in less clutter and increased airflow in the computer system, because SATA cables are 400 percent narrower than EIDE cables. Some older computer system motherboards don't have SATA ports, but a PCI SATA controller card can be installed to add support for SATA drives. If you don't know whether your computer has SATA ports on the motherboard, refer to your computer or motherboard documentation or contact the motherboard manufacturer.
EIDE Interface
Enhanced integrated drive electronics (EIDE), also called Parallel ATA (PATA), hard drives have been the standard in the home computer industry for more than 10 years. Some newer computer system motherboards don't have EIDE ports, but a PCI EIDE controller card can be installed to add support for EIDE drives. If you don't know whether your computer has EIDE ports on the motherboard, refer to your computer or motherboard documentation or contact the motherboard manufacturer.