Skip to content

Data Storage Terms

data storage terms

This resource was created to help you confidently navigate the world of computer data storage. We have provided the terms and definitions to over two dozen words on this subject. Be sure to download the free flashcards below and when you are ready, take the quiz to see how well you know the material.


Data Storage Terms



areal density

Areal density measures the information quantity in gigabits per square inch as a means to describe hard drive capacity. Higher density is better from the standpoint of a smaller storage medium holding more data which is less expensive to run and maintain.

backup software

Backup software provides a programatic way to conveniently set up a backup plan, be it full, mirror, incremental or differential. Some available backup tools are TotalRecovery Pro, Symantec Backup Exec and Norton Ghost to name a few.

backup strategy

A backup strategy helps prevent data loss that could result from hardware failure, a natural disaster or cyberattack. A good plan for most people would be to incorporate the 3-2-1 rule. Three copies of your data, with two local copies on different devices and one copy off-site.

cache memory

Cache memory stores some regularly used data and instructions for faster availability and processing to the CPU instead of it being served up using the slower Random Access Memory (RAM).

cloud storage

Cloud storage is a data storage and management service that is accessed over the internet. This eliminates the overhead cost of maintaining the servers of data themselves.

data recovery

Data recovery is the process of refreshing lost data. The data could have been lost as a result of a natural disaster, unexpected computer crash, cyberattack, corruption or accidental deletion.

data storage

Data storage is the digital repository of electronic documents and files of many kinds. Data storage can reside on internal drives, external drives, USB drives or in a cloud service to name a few.

direct attached storage (DAS)

Direct Attached Storage (DAS) is data storage (like external hard drives, USB drives and more) that is directly attached to the computer.

external hard drive

An external hard drive adds more data storage to your home computer system. They are used to store infrequently used files, video game storage, and of course backing up a desktop or laptop.

external hard drive manufacturers

Some of the top external hard drive manufacturers are Western Digital, Seagate, Transcend, Toshiba, Lenovo, G-Technology, SanDisk, Adata, Samsung to name a few.

hard disk drive (HDD)

Simply put a hard disk drive is a means to store data digitally. It is an electro-mechanical system meaning that it uses an electronic signal to then cause a physical mechanical movement to write or read from rotating magnetic coated platters. Contrast this to the faster solid state drive which has no moving parts.

hard drive manufacturers

Some of the top hard drive manufacturers are Hewlett-Packard (HP), Western-Digital, SanDisk, Seagate, Toshiba, Seagate, Sony, Hitachi, Kingston Technology to name a few.

hardware encryption

Hardware encryption prevents unauthorized data access by converting data into a code. When this happens within a drive it is called hardware encryption.


HDD stands for “hard disk drive” which is a type of computer data storage. See: “Hard Disk Drive”.

hybrid drive (SSHD)

A hybrid drive is a data storage technology that combines the faster Solid State Drive (SSD) and the larger capacity Hard Disk Drive (HDD). It typically can distinguish between data elements that are more frequently used to be stored in SSD and other long term data stored in HDD. Western Digital’s Black drive is a good example of a dual SSD/HDD configuration which is especially desired in gaming applications.

internal storage hard drive

An internal storage hard drive is the primary data storage inside of a laptop, desktop, workstation or server.

internal storage

See: internal storage hard drive

mechanical hard drive

mechanical hard drive: See: “Hard Disk Drive”. In short, a HDD has moving parts unlike the “Solid State Drive” (SSD) that is much faster and has no moving parts.

nand flash

nand flash is memory storage technology that does not need electrical power in order to keep its data intact. Mobile phones use microSD cards which is nand flash technology that retains all its data of videos, music and pictures even when the phone is powered off.

network attached storage (NAS)

A network attached storage device (NAS) is a computer data storage server that stores and shares data over a network. Data can then be easily accessed by multiple people and computers. An advantage of NAS is the centralization of data which improves collaboration.

raid drive

RAID drive data storage combines multiple physical drive components but the computer sees it as one volume.

read speed

read speed is the measurement of the time that it takes to open a file. See also: write speed

rpm (drive rpm)

revolutions per minute is the number of rotational turns that take place in one minute. In this case of a mechanical hard drive. The average hard drive spin rate speed is between 5,400 and 7,200 revolutions per minute.


SAS is a type of data transfer technology designed to transfer data between storage and a motherboard. SAS is used primarily in servers. See also: SATA


SATA is a type of data transfer technology designed to transfer data between storage and a motherboard. SATA is used primarily in desktop computer configurations. See also: SAS

solid state drive (SSD)

Unlike mechanical hard disk drives that have spinning parts, solid state drives use flash based technology and conversely has no moving parts. SSD is known to have very fast data read/write speeds compared to HDD.

spindle speed

Spindle speed measured in RPM, is simply how fast hard drive platters or disks spin during normal operation. This speed rate will show how fast the hard drive perform read and write operations on the computer.

storage capacity

Storage capacity measures how much data a computer system can store. Most computers today express storage capacity in terabytes. 1 terabyte = 1,000 gigabytes. For perspective, according to dropbox: “1 TB roughly can store 250,000 photos taken with a 12MP camera; or 250 movies or 500 hours of HD video or 6.5 million document pages.”

write speed

write speed is the measurement of the time that it takes to save data to a computer storage. See also: read speed

Free Flashcard Download!

smart human with computer brain

Data Storage Terms Quiz

Take the Data Storage Terms knowledge quiz challenge!