Storage Technology Definitions

This glossary explains the meaning of key words and phrases that information technology (IT) and business professionals use when discussing storage and related software products. You can find additional definitions by visiting WhatIs.com or using the search box below.

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  • S

    What is a SAN? Ultimate storage area network guide

    A storage area network (SAN) is a dedicated high-speed network or subnetwork that interconnects and presents shared pools of storage devices to multiple servers.

  • What is SSD RAID (solid-state drive RAID)?

    SSD RAID (solid-state drive RAID) is a methodology commonly used to protect data by distributing redundant data blocks across multiple SSDs.

  • What is storage virtualization?

    Storage virtualization is the pooling of physical storage from multiple storage devices into what appears to be a single storage device or pool of available storage capacity.

  • T

    tape drive

    A tape drive is a device that stores computer data on magnetic tape, especially for backup and archiving purposes.

  • tebibyte (TiB)

    A tebibyte (TiB) is a unit of measure used to describe computing capacity.

  • Terabyte (TB)

    A terabyte (TB) is a unit of digital data that is equal to about 1 trillion bytes.

  • Tier 0

    Tier 0 is a level of data storage that is faster, and perhaps more expensive, than any other level in the storage hierarchy.

  • tiered storage

    Tiered storage is a method for assigning different categories of data to various types of storage media to reduce overall storage costs and improve the performance and availability of mission-critical applications.

  • TLC flash (triple-level cell flash)

    TLC flash (triple-level cell flash) is a type of NAND flash memory that stores three bits of data per cell.

  • U

    unified storage

    Unified storage -- sometimes called network unified storage or multiprotocol storage -- is a storage system that enables users to run and manage files and applications from a single device.

  • USB flash drive

    A USB flash drive -- also known as a stick, thumb or pen drive -- is a plug-and-play portable storage device that uses flash memory and can attach to a keychain.

  • utility storage

    Utility storage is a service model in which a provider makes storage capacity available to an individual, organization or business unit on a pay-per-use basis.

  • What is U.2 SSD (formerly SFF-8639)?

    A U.2 SSD is a high-performance data storage device designed to support the Peripheral Component Interconnect Express (PCIe) interface using a small form factor (SFF) connector that is also compatible with standard SAS and SATA-based spinning disks and solid-state drives (SSDs).

  • V

    virtual LUN (virtual logical unit number)

    A virtual LUN (virtual logical unit number) is a representation of a storage area that is not tied to any physical storage allocation.

  • virtual SAN appliance (VSA)

    A virtual SAN appliance (VSA) is a software bundle that allows a storage manager to turn the unused storage capacity in his network's virtual servers into a storage area network (SAN).

  • virtual storage area network (VSAN)

    A virtual storage area network (VSAN) is a logical partition in a physical storage area network (SAN).

  • VRAM (video RAM)

    VRAM (video RAM) refers to any type of random access memory (RAM) specifically used to store image data for a computer display.

  • What is virtual memory?

    Virtual memory is a memory management technique where secondary memory can be used as if it were a part of the main memory.

  • W

    What is wear leveling?

    Wear leveling is a process that is designed to extend the life of solid-state storage devices.

  • World Wide Name (WWN)

    A World Wide Name (WWN) is a unique identifier that is hard-coded into each Fibre Channel (FC) device by the device's manufacturer.

  • WORM (write once, read many)

    In computer media, write once, read many, or WORM, is a data storage technology that allows data to be written to a storage medium a single time and prevents the data from being erased or modified.

  • write amplification factor (WAF)

    Write amplification factor (WAF) is a numerical value that represents the amount of data a solid-state drive (SSD) controller writes in relation to the amount of data that the host's flash controller writes.

  • write endurance

    Write endurance is the number of program/erase (P/E) cycles that can be applied to a block of flash memory before the storage media becomes unreliable.

  • Y

    yobibyte (YiB)

    A yobibyte (YiB) is a unit of measure used to describe data capacity as part of the binary system of measuring computing and storage capacity.

  • yottabyte (YB)

    A yottabyte (YB) is a measure of theoretical storage capacity and data volumes equal to 2 to the 80th power bytes, or approximately a million trillion megabytes (MB).

  • Z

    What is ZFS?

    ZFS is a local file system and logical volume manager created by Sun Microsystems to direct and control the placement, storage and retrieval of data in enterprise-class computing systems.

  • zebibyte (ZiB)

    A zebibyte (ZiB) is a unit used to measure computing and storage capacity.

  • zettabyte

    A zettabyte is a unit of measurement used by technology professionals and the general public to describe a computer or other device's storage capacity.