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Data storage

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Many different consumer electronic devices can store data.
Edison cylinder phonograph ca. 1899. The Phonograph cylinder is a storage medium. The phonograph may or may not be considered a storage device.
A reel-to-reel tape recorder (Sony TC-630). The magnetic tape is a storage medium. The recorder is data storage equipment using a portable medium (tape reel) to store the data.
Crafting tools such as paint brushes can be used as data storage equipment. The paint and canvas can be used as data storage media.
DNA may be the oldest data storage medium.

A data storage device is a device for recording (storing) information (data). Recording can be done using virtually any form of energy. A storage device may hold information, process information, or both. A device that only holds information is a recording medium. Devices that process information (data storage equipment) may either access a separate portable (removable) recording medium or a permanent component to store and retrieve information.

Electronic data storage is storage that requires electrical power to store and retrieve data. Most storage devices that do not require visual optics to read data fall into this category. Electronic data may be stored in either an analog or digital signal format. This type of data is considered to be electronically encoded data, whether or not it is electronically stored. Most electronic data storage media is considered permanent (non-volatile) storage, that is, the data will remain stored when power is removed from the device. In contrast, electronically stored information is considered volatile memory.

With the exception of barcodes and OCR data, electronic data storage is easier to revise and may be more cost effective than alternative methods due to smaller physical space requirements and the ease of replacing (rewriting) data on the same medium. However, the durability of methods such as printed data is still superior to that of most electronic storage media. The durability limitations may be overcome with the ease of duplicating (backing-up) electronic data.

Terminology

Devices that are not used exclusively for recording (e.g. hands, mouths, musical instruments) and devices that are intermediate in the storing/retrieving process (e.g. eyes, ears, cameras, scanners, microphones, speakers, monitors, projectors) are not usually considered storage devices. Devices that are exclusively for recording (e.g. printers), exclusively for reading (e.g. barcode readers), or devices that process only one form of information (e.g. phonographs) may or may not be considered storage devices. In computing these are known as input/output devices.

An organic brain may or may not be considered a data storage device.[1]

All information is data. However, not all data is information.

Data storage equipment

The equipment that accesses (reads and writes) storage information are often called storage devices. Data storage equipment uses either:

  • portable methods (easily replaced),
  • semi-portable methods requiring mechanical disassembly tools and/or opening a chassis, or
  • inseparable methods meaning loss of memory if disconnected from the unit.

The following are examples of those methods:

Portable methods

Semi-portable methods

Inseparable methods

Recording medium

A recording medium is a physical material that holds data expressed in any of the existing recording formats. With electronic media, the data and the recording medium is sometimes referred to as "software" despite the more common use of the word to describe computer software. With (traditional art) static media, art materials such as crayons may be considered both equipment and medium as the wax, charcoal or chalk material from the equipment becomes part of the surface of the medium.

Some recording media may be temporary either by design or by nature. Volatile organic compounds may be used to preserve the environment or to purposely make data expire over time. Data such as smoke signals or skywriting are temporary by nature. Depending on the volatility, a gas (e.g. atmosphere, smoke) or a liquid surface such as a lake would be considered a temporary recording medium if at all.

Ancient and timeless examples

The Gutenberg Bible displayed by the United States Library of Congress. The book is a data storage medium.

Modern examples by energy used

File:Graffiti Panorama rome.jpg
Graffiti on a public wall. Public surfaces are being used as unconventional data storage media, often without permission.
Photographic film is a photochemical data storage medium
A floppy disk is a magnetic data storage medium
Hitachi 2.5 inch laptop hard drive. A hard drive is both storage equipment and a storage medium
File:Flash-Media-Cards.jpg
Four major types of memory cards (from left to right: CompactFlash, MemoryStick, Secure Digital, and xD.
Picture of a Holographic Versatile Disc by Optware.

Modern examples by shape

A typical way to classify data storage media is to consider its shape and type of movement (or non-movement) relative to the read/write device(s) of the storage apparatus as listed:

Bekenstein (2003) foresees that miniaturization might lead to the invention of devices that store bits on a single atom.

See also

References

  • Bekenstein, Jacob D. (2003, August). Information in the holographic universe. Scientific American.

Bibliography

  • Bennett, John C. (1997). "'JISC/NPO Studies on the Preservation of Electronic Materials: A Framework of Data Types and Formats, and Issues Affecting the Long Term Preservation of Digital Material". British Library Research and Innovation Report 50. {{cite journal}}: Cite journal requires |journal= (help)
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