Disk storage is a data storage mechanism based on a rotating disk. The recording employs various electronic, magnetic, optical, or mechanical changes to the disk's surface layer. A disk drive is a device implementing such a storage mechanism. Notable types are hard disk drives (HDD), containing one or more non-removable rigid platters; the floppy disk drive (FDD) and its removable floppy disk; and various optical disc drives (ODD) and associated optical disc media.
A hard disk drive (HDD), hard disk, hard drive, or fixed disk is an electro-mechanical data storage device that stores and retrieves digital data using magnetic storage with one or more rigid rapidly rotating platters coated with magnetic material. The platters are paired with magnetic heads, usually arranged on a moving actuator arm, which read and write data to the platter surfaces. Data is accessed in a random-access manner, meaning that individual blocks of data can be stored and retrieved in any order. HDDs are a type of non-volatile storage, retaining stored data when powered off. Modern HDDs are typically in the form of a small rectangular box.
The Zip drive is a removable floppy disk storage system that was announced by Iomega in 1994 and began shipping in March 1995. Considered medium-to-high-capacity at the time of its release, Zip disks were originally launched with capacities of 100 MB, then 250 MB, and finally 750 MB.
The Bernoulli Box is a high-capacity removable floppy disk storage system that is Iomega's first widely known product. It was released in 1982.
A magneto-optical drive is a kind of optical disc drive capable of writing and rewriting data upon a magneto-optical disc. 130 mm (5.25 in) and 90 mm (3.5 in) discs were the most common sizes. In 1983, just a year after the introduction of the compact disc, Kees Schouhamer Immink and Joseph Braat presented the first experiments with erasable magneto-optical compact discs during the 73rd AES Convention in Eindhoven. The technology was introduced commercially in 1985. Although optical, they normally appear as hard disk drives to an operating system and can be formatted with any file system. Magneto-optical drives were common in some countries, such as Japan, but have fallen into disuse.
A flash drive is a data storage device that includes flash memory with an integrated USB interface. A typical USB drive is removable, rewritable, and smaller than an optical disc, and usually weighs less than 30 g (1 oz). Since first offered for sale in late 2000, the storage capacities of USB drives range from 8 megabytes to 256 gigabytes (GB), 512 GB and 1 terabyte (TB). As of 2023, 2 TB flash drives were the largest currently in production. Some allow up to 100,000 write/erase cycles, depending on the exact type of memory chip used, and are thought to physically last between 10 and 100 years under normal circumstances.
DVD-RAM is a DVD-based disc specification presented in 1996 by the DVD Forum, which specifies rewritable DVD-RAM media and the appropriate DVD writers. DVD-RAM media have been used in computers as well as camcorders and personal video recorders since 1998.
SyQuest Technology, Inc. (Nasdaq: SYQT) was an early entrant into the hard disk drive market for personal computers. The company was founded on January 27, 1982 by Syed Iftikar who had been a founder of Seagate, along with Ben Alaimo, Bill Krajewski, Anil Nigam and George Toldi. Its earliest products were the SQ306R, a 5 MB 3.9" (100 mm) cartridge disk drive and associated Q-Pak cartridge for IBM XT compatibles. Subsequently a non-removable medium version was announced, the SQ306F.
Iomega Corporation was a company that produced external, portable, and networked data storage products. Established in the 1980s in Roy, Utah, United States, Iomega sold more than 410 million digital storage drives and disks, including the Zip drive floppy disk system. Formerly a public company, it was acquired by EMC Corporation in 2008, and then by Lenovo, which rebranded the product line as LenovoEMC, until discontinuation in 2018.
The Jaz drive is a removable hard disk storage system sold by the Iomega company from 1995 to 2002.
A disk enclosure is a specialized casing designed to hold and power hard disk drives or solid state drives while providing a mechanism to allow them to communicate to one or more separate computers.
The USB mass storage device class is a set of computing communications protocols, specifically a USB Device Class, defined by the USB Implementers Forum that makes a USB device accessible to a host computing device and enables file transfers between the host and the USB device. To a host, the USB device acts as an external hard drive; the protocol set interfaces with a number of storage devices.
The Ditto drive series was a proprietary magnetic tape data storage system released by Iomega during the 1990s. It was marketed as a backup device for personal computers.
The Western Digital Raptor is a discontinued series of high performance hard disk drives produced by Western Digital first marketed in 2003. The drive occupied a niche in the enthusiast, workstation and small-server market. Traditionally, the majority of servers used hard drives featuring a SCSI interface because of their advantages in both performance and reliability over consumer-level ATA drives.
In computing, external storage refers to non-volatile (secondary) data storage outside a computer's own internal hardware, and thus can be readily disconnected and accessed elsewhere. Such storage devices may refer to removable media, compact flash drives, portable storage devices, or network-attached storage. Web-based cloud storage is the latest technology for external storage.
Ultra Density Optical (UDO) is an optical disc format designed for high-density storage of high-definition video and data. The format was introduced by Sony to replace the Magneto-optical disc format.
The EZ 135 Drive is a 3.5" removable platter hard disk drive. It was introduced by SyQuest Technology in 1995. It had a maximum capacity of 135 MB per disk.
The Orb Drive is a 3.5-inch removable hard-disk drive introduced by Castlewood Systems in 1999. Its original capacity was 2.2 GB. A later version of the drive was introduced in 2001 with a capacity of 5.7 GB. Manufacturing of this product ceased in 2004.
RDX is a disk-based removable storage format developed by ProStor Systems Incorporated in 2004. In May 2011, Tandberg Data GmbH acquired the RDX business from ProStor Systems including intellectual property and key members of ProStor's RDX engineering team. RDX is intended as a replacement of tape storage. RDX removable disk technology consists of portable disk cartridges and an RDX dock. RDX cartridges are shock-proof 2.5-inch Serial ATA hard disk drives and are advertised to sustain a 1 meter (39 in) drop onto a concrete floor and to offer an archival lifetime up to 30 years and transfer up to 650GB/hr.
The Seagate Barracuda is a series of hard disk drives and later solid state drives produced by Seagate Technology that was first introduced in 1993.
