Hard Disk

A hard disk is a non-volatile storage device which stores digitally programmed data on rapidly rotating platters with magnetic surfaces. Strictly speaking, "drive" refers to a device that drives (removable) media, such as a tape drive or (floppy) disk drive, although a hard disk contains fixed (non-removable) media. Recently the hard disk has become more commonly known as the "hard drive".

Hard disks were initially developed for use with computers. In the 21st century, applications for hard disks have extended beyond computers to consist of digital video recorders, digital audio players, personal digital assistants, digital cameras, and video game consoles. In 2005 the first mobile phones to contain hard disks were introduced by Samsung Group and Nokia. The need for large-scale, reliable storage, independent of a particular device, led to the beginning of configurations such as RAID, hardware such as network attached storage (NAS) devices, and systems such as storage area networks (SANs) for efficient access to large volumes of data.