A data storage device is a device for recording (storing) information (data). Recording can be done using virtually any form of energy, spanning from manual muscle power in handwriting, to acoustic vibrations in phonographic recording, to electromagnetic energy modulating magnetic tape and optical discs.

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 which requires electrical power to store and retrieve that data. Most storage devices that do not require vision and a brain to read data fall into this category. Electromagnetic data may be stored in either an analog or digital format on a variety of media. This type of data is considered to be electronically encoded data, whether or not it is electronically stored in a semiconductor device, for it is certain that a semiconductor device was used to record it on its medium. Most electronically processed data storage media (including some forms of computer data storage) are considered permanent (non-volatile) storage, that is, the data will remain stored when power is removed from the device. In contrast, most electronically stored information within most types of semiconductor (computer chips) microcircuits are volatile memory, for it vanishes if power is removed.

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.

Noun

capacity (plural capacities)

1. The ability to hold, receive or absorb
2. A measure of such ability; volume
3. The maximum amount that can be held

   It was hauling a capacity load.

   The orchestra played to a capacity crowd.

4. Capability; the ability to perform some task
5. The maximum that can be produced.
6. Mental ability; the power to learn
7. A faculty; the potential for growth and development
8. A role; the position in which one functions
9. Legal authority (to make an arrest for example)
10. Electrical capacitance.
11. (operations) The maximum that can be produced on a machine or in a facility or group.

    Its capacity rating was 150 tons per hour, but its actual maximum capacity was 200 tons per hour.

• throughput
• See also Wikisaurus:skill

• Benchmarking (26)
• Capacity Planning (14)
• CPU Saturation Models (1)
• Response Time Models (0)

• Computers: Programming: Software Testing: Load and Performance Testing (29)
• Computers: Software: Networking: Network Performance (54)

• ATL-CSIM: System Simulation and Modeling Tools.
  atl.external.lmco.com
  Lockheed Advanced Technology Labs' CSIM is a general purpose discrete-event simulator for block diagram oriented systems. Graphical/interactive or text/batch simulations. Not to be confused with Mesquite Software's CSIM18, another simulation tool.
• Stratton & English Software - Performance Specialists
  strattonenglish.co.uk
  Provider of Internet Software Services, specialising in Performance Investigations - including performance prediction, optimisation and testing.
• Quantitative System Performance
  cs.washington.edu
  Introductory text on analytic computer performance models. Complete text is available as searchable PDF. Published in 1984.