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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  • #

    3D NAND flash

    3D NAND is a type of non-volatile flash memory in which the memory cells are stacked vertically in multiple layers.

  • 3D XPoint

    3D XPoint is memory storage technology that was jointly developed by Intel and Micron Technology. The two vendors intended for the technology to fill a gap in the storage market between dynamic RAM (DRAM) and NAND flash.

  • A

    address space

    Address space is the amount of memory allocated for all possible addresses for a computational entity -- for example, a device, a file, a server or a networked computer.

  • Advanced Host Controller Interface (AHCI)

    Advanced Host Controller Interface, or AHCI, is a technical standard for an interface that enables software to communicate with Serial ATA (SATA) devices.

  • all-flash array (AFA)

    An all-flash array (AFA), also known as a solid-state storage disk system or a solid-state array, is an external storage array that supports only flash media for persistent storage.

  • archive

    An archive is a collection of data moved to a repository for long-term retention, to be kept separate for compliance reasons or moved off primary storage media.

  • B

    bad block

    A bad block is an area of storage media that is no longer reliable for storing and retrieving data because it has been physically damaged or corrupted.

  • bare-metal cloud

    Bare-metal cloud is a public cloud service that offers dedicated hardware resources without any installed operating systems or virtualization infrastructure.

  • bare-metal restore

    A bare-metal restore (also referred to as bare-metal recovery or bare-metal backup) is a data recovery and restoration process where a computer is restored to a new machine, typically after a catastrophic failure.

  • big data storage

    Big data storage is a compute-and-storage architecture that collects and manages large data sets and enables real-time data analytics.

  • block storage

    Block storage is an approach to data storage in which each volume acts as an individual hard drive that is configured by the administrator.

  • blockchain storage

    Blockchain storage is a way of saving data in a decentralized network, which utilizes the unused hard disk space of users across the world to store files.

  • brontobyte

    A brontobyte is an unofficial measure of memory or data storage that is equal to 10 to the 27th power of bytes.

  • business impact analysis (BIA)

    A business impact analysis (BIA) is a systematic process to determine and evaluate the potential effects of an interruption to critical business operations as a result of a disaster, accident or emergency.

  • byte

    In most computer systems, a byte is a unit of data that is eight binary digits long.

  • What is bit rot?

    Bit rot is the slow deterioration in the performance and integrity of data stored on storage media.

  • C

    cache

    A cache -- pronounced CASH -- is hardware or software that is used to store something, usually data, temporarily in a computing environment.

  • cache memory

    Cache memory is a chip-based computer component that makes retrieving data from the computer's memory more efficient.

  • capacity management

    Capacity management is the broad term describing a variety of IT monitoring, administration and planning actions that ensure that a computing infrastructure has adequate resources to handle current data processing requirements, as well as the capacity to accommodate future loads.

  • charge-coupled device

    A charge-coupled device (CCD) is a light-sensitive integrated circuit that captures images by converting photons to electrons.

  • cloud archive

    A cloud archive is storage as a service for long-term data retention.

  • cloud data management

    Cloud data management is a way to manage data across cloud platforms, either with or instead of on-premises storage.

  • Cloud Data Management Interface (CDMI)

    The Cloud Data Management Interface (CDMI) is an international standard that defines a functional interface that applications use to create, retrieve, update and delete data elements from cloud storage.

  • cloud encryption

    Cloud encryption is a service cloud storage providers offer whereby a customer's data is transformed using encryption algorithms from plaintext into ciphertext and stored in the cloud.

  • cloud hosting

    Cloud hosting is the process of outsourcing an organization's computing and storage resources to a service provider that offers its infrastructure services in a utility model.

  • cloud NAS (cloud network attached storage)

    Cloud NAS (network attached storage) is remote storage that is accessed over the internet as if it is local.

  • cloud object storage

    Cloud object storage is a format for storing unstructured data in the cloud. Object storage is considered a good fit for the cloud because it is elastic, flexible and it can more easily scale into multiple petabytes to support unlimited data growth.

  • cloud SLA (cloud service-level agreement)

    A cloud SLA (cloud service-level agreement) is an agreement between a cloud service provider and a customer that ensures a minimum level of service is maintained.

  • cloud storage

    Cloud storage is a service model in which data is transmitted and stored on remote storage systems, where it is maintained, managed, backed up and made available to users over a network (typically the internet).

  • cloud storage API

    A cloud storage API is an application programming interface that connects a locally based application to a cloud-based storage system so that a user can send data to it and access and work with data stored in it.

  • cloud storage provider

    A cloud storage provider, sometimes referred to as a managed service provider, is a company that offers organizations and individuals the ability to place and retain data in an off-site storage system.

  • cloud storage service

    A cloud storage service is a business that maintains and manages its customers' data and makes that data accessible over a network, usually the internet.

  • cloud washing

    Cloud washing (also spelled cloudwashing) is the purposeful and sometimes deceptive attempt by a vendor to rebrand an old product or service by associating the buzzword 'cloud' with it.

  • clustered network-attached storage (NAS) system

    A clustered network-attached storage (NAS) system is a scale-out storage platform made up of multiple NAS nodes networked together into a single cluster.

  • cold storage

    Cold storage is a computer system or mode of operation designed for the retention of inactive data.

  • Common Information Model (CIM)

    The Common Information Model (CIM) is a computer industry standard that defines device and application characteristics so system administrators and management programs can control devices and applications from different manufacturers.

  • Common Internet File System (CIFS)

    CIFS (Common Internet File System) is a protocol that gained popularity around the year 2000, as vendors worked to establish an Internet Protocol-based file-sharing protocol.

  • compact disc (CD)

    A compact disc is a portable storage medium that can record, store and play back audio, video and other data in digital form.

  • computational storage

    Computational storage is an IT architecture in which data is processed at the storage device level to reduce the amount of data that must move between the storage plane and the compute plane.

  • content-addressed storage (CAS)

    Content-addressed storage (CAS) -- also called content-addressable storage -- is a method for storing fixed content as objects and providing fast access to that content.

  • converged network adapter (CNA)

    A converged network adapter (CNA) is a single network interface device that provides the functionality of both a Fibre Channel (FC) host bus adapter (HBA) and a TCP/IP Ethernet network interface card (NIC).

  • copy data management (CDM)

    Copy data management (CDM) is an approach to reducing storage consumption that involves eliminating the unnecessary duplication of production data.

  • What is a CompactFlash card (CF card)?

    A CompactFlash card (CF card) is a memory card format developed by SanDisk in 1994 that uses flash memory technology to store data on a very small portable device.

  • What is Ceph?

    Ceph is an open source software solution that provides a unified system for enterprise-level object, block- and file-based storage.

  • What is cloud testing? An introduction to testing in the cloud

    Cloud testing is the process of using the cloud computing resources of a third-party service provider to test software applications.

  • What is continuous data protection (CDP)?

    Continuous data protection (CDP), also known as 'continuous backup,' is a backup and recovery storage system in which all the data in an enterprise is backed up whenever any change is made.

  • D

    data at rest

    Data at rest is a term that is sometimes used to refer to all data in computer storage while excluding data that is traversing a network or temporarily residing in computer memory to be read or updated.

  • data availability

    Data availability is a term used by computer storage manufacturers and storage service providers to describe how data should be available at a required level of performance in situations ranging from normal through disastrous.

  • data compression

    Data compression is a reduction in the number of bits needed to represent data.

  • data deduplication

    Data deduplication is a process that eliminates redundant copies of data and reduces storage overhead.

  • data destruction

    Data destruction is the process of destroying data stored on tapes, hard disks and other forms of electronic media so that it's completely unreadable and can't be accessed or used for unauthorized purposes.

  • Data Dynamics StorageX

    Data Dynamics StorageX is a software suite that specializes in data migration and Microsoft Distributed File System management.

  • data lifecycle management (DLM)

    Data lifecycle management (DLM) is a policy-based approach to managing the flow of an information system's data throughout its lifecycle: from creation and initial storage to when it becomes obsolete and is deleted.

  • data management platform (DMP)

    A data management platform (DMP), also referred to as a unified data management platform (UDMP), is a centralized system for collecting and analyzing large sets of data originating from disparate sources.

  • data migration

    Data migration is the process of transferring data between data storage systems, data formats or computer systems.

  • dedicated cloud

    A dedicated cloud is a single-tenant cloud infrastructure, which essentially acts as an isolated, single-tenant public cloud.

  • DIMM (dual in-line memory module)

    DIMM, or dual in-line memory module, is a type of computer memory that is natively 64 bits, enabling fast data transfer.

  • direct access

    In computer storage, direct access is the process of reading and writing data on a storage device by going directly to where the data is physically located on the device rather than having to move sequentially from one physical location to the next to find the correct data.

  • direct access storage device (DASD)

    A direct access storage device (DASD) is a type of secondary storage device that supports direct access to the stored data, as opposed to sequential access, which is slower and less efficient.

  • direct-attached storage (DAS)

    Direct-attached storage (DAS) is a type of storage that is attached directly to a computer without going through a network.

  • disk array

    A disk array, also called a storage array, is a data storage system used for block-based storage, file-based storage or object storage.

  • disk mirroring (RAID 1)

    Disk mirroring, also known as RAID 1, is the replication of data across two or more disks.

  • distributed file system (DFS)

    A distributed file system (DFS) is a file system that enables clients to access file storage from multiple hosts through a computer network as if the user was accessing local storage.

  • DRAM (dynamic random access memory)

    DRAM (dynamic random access memory) is a type of semiconductor memory that is typically used for the data or program code needed by a computer processor to function.

  • E

    email archiving

    Email archiving is a systematic approach to saving and protecting the data contained in emails to enable fast retrieval.

  • enterprise storage

    Enterprise storage is a centralized repository for business information that provides common data management, protection and sharing functions through connections to computer systems.

  • erasure coding (EC)

    Erasure coding (EC) is a method of data protection in which data is broken into fragments, expanded and encoded with redundant data pieces, and stored across a set of different locations or storage media.

  • exabyte (EB)

    An exabyte (EB) is a large unit of computer data storage, two to the sixtieth power bytes.

  • exbibyte (EiB)

    An exbibyte (EiB) is a unit that measures data capacity.

  • external storage device

    An external storage device, also referred to as auxiliary storage and secondary storage, is a device that contains all the addressable data storage that is not inside a computer's main storage or memory.

  • What is an embedded MultiMediaCard (eMMC)?

    An embedded MultiMediaCard (eMMC) is a small storage device made up of NAND flash memory and a storage controller.

  • F

    failover

    Failover is a backup operational mode in which the functions of a system component are assumed by a secondary component when the primary becomes unavailable.

  • Fibre Channel

    Fibre Channel is a high-speed networking technology primarily used for transmitting data among data centers, computer servers, switches and storage at data rates of up to 128 Gbps.

  • Fibre Channel (FC) port types

    A Fibre Channel port is a hardware pathway into and out of a node that performs data communications over an FC link.

  • Fibre Channel over Ethernet (FCoE)

    Fibre Channel over Ethernet (FcoE) is a storage protocol that enables Fibre Channel (FC) communications to run directly over Ethernet.

  • Fibre Channel switch (FC switch)

    A Fibre Channel (FC) switch is a networking device that's compatible with the FC protocol and designed for use in a dedicated storage area network (SAN).

  • file synchronization (file sync)

    File synchronization (file sync) is a method of keeping files that are stored in several different physical locations up to date.

  • file system

    In computing, a file system -- sometimes written filesystem -- is a logical and physical system for organizing, managing and accessing the files and directories on a device's solid-state drive (SSD), hard-disk drive (HDD) or other media.

  • flash controller (flash memory controller)

    A flash controller is the part of solid-state flash memory that communicates with the host device and manages the flash file system directory.

  • flash memory

    Flash memory, also known as flash storage, is a type of nonvolatile memory that erases data in units called blocks and rewrites data at the byte level.

  • flash memory card

    A flash memory card -- sometimes called a storage card -- is a small storage device that uses non-volatile semiconductor memory to store data on portable or remote computing devices.

  • flash solid-state drive (SSD)

    A flash solid-state drive (SSD) is a non-volatile storage device that stores persistent data in flash memory.

  • flash storage

    Flash storage is any type of drive, repository or system that uses flash memory to write and store data for an extended period.

  • floating gate transistor (FGT)

    A floating gate transistor (FGT) is a complementary metal-oxide semiconductor (CMOS) technology capable of holding an electrical charge in a memory device that is used to store data.

  • G

    garbage collection (GC)

    Garbage collection (GC) is a memory recovery feature built into programming languages such as C# and Java.

  • gibibyte (GiB)

    A gibibyte (GiB) is a unit of measure of capacity in computing.

  • gigabyte (GB)

    A gigabyte (GB) -- pronounced with two hard Gs -- is a unit of data storage capacity that is roughly equivalent to 1 billion bytes.

  • Google Cloud Storage

    Google Cloud Storage is an enterprise public cloud storage platform that can house large unstructured data sets.

  • green cloud

    Green cloud refers to the potential environmental benefits that green IT services delivered over the internet can offer to individual companies and society as a whole.

  • H

    Hadoop as a service (HaaS)

    Hadoop as a service (HaaS), also known as Hadoop in the cloud, is a big data analytics framework that stores and analyzes data in the cloud using Hadoop.

  • hard disk drive (HDD)

    A computer hard disk drive (HDD) is a non-volatile data storage device.

  • hardware RAID (hardware redundant array of independent disk)

    Hardware RAID is a form of RAID (redundant array of independent disks) where processing is done on the motherboard or a separate RAID card.

  • HD-DVD (high-definition DVD)

    HD-DVD (high-definition DVD) is a defunct high-capacity optical storage medium that was once seen as the successor to the DVD.

  • HDD form factor (hard disk drive form factor)

    HDD form factor (hard disk drive form factor) is the size or geometry of a data storage device equipped with one or more magnetic-coated spinning platters and one or more moving actuator arms with magnetic heads to read and write information.

  • hierarchical storage management (HSM)

    Hierarchical storage management (HSM) is policy-based management of data files that uses storage media economically and without the user being aware of when files are retrieved from storage.

  • holographic storage (holostorage)

    Holographic storage is computer storage that uses laser beams to store computer-generated data in three dimensions.

  • host bus adapter (HBA)

    A host bus adapter (HBA) is a circuit board or integrated circuit adapter that connects a host system, such as a server, to a storage or network device.

  • hot plugging

    Hot plugging is the addition of a component to a running computer system without significant interruption to the operation of the system.

  • How many bytes for...

    Data is often expressed in bytes, which are composed of eight binary digits.

  • hybrid cloud storage

    Hybrid cloud storage is an approach to managing cloud storage that uses both local and off-site resources.