Computer Devices
Peripheral
A peripheral is a "device that is used to put information into or get information out of the computer."[11]There are three different types of peripherals:- Input, used to interact with, or send data to the computer (mouse, keyboards, etc.)
- Output, which provides output to the user from the computer (monitors, printers, etc.)
- Storage, which stores data processed by the computer (hard drives, flash drives, etc.)
Overview
A peripheral device is generally defined as any auxiliary device such as a computer mouse or keyboard, that connects to and works with the computer in some way. Other examples of peripherals are expansion cards, graphics cards, image scanners, tape drives, microphones, loudspeakers, webcams, and digital cameras. RAM—random access memory—straddles the line between peripheral and primary component; it is technically a storage peripheral, but is required for every major function of a modern computer and removing the RAM will effectively disable any modern machine. Many new devices such as digital watches, smartphones and tablet computers have interfaces which allow them to be used as a peripheral by a full computer, though they are not host-dependent as other peripheral devices are. According to the most technical definition, the only pieces of a computer notconsidered to be peripherals are the central processing unit, power supply, motherboard, and computer case.Usually, the word peripheral is used to refer to a device external to the computer case, like a scanner, but the devices located inside the computer case are also technically peripherals. Devices that exist outside the computer case are called external peripherals, or auxiliary components, Examples are: "Many of the external peripherals I own, such as my scanner and printer, connect to the peripheral ports on the back of my computer."[12] Devices that are inside the case such as internal hard drives or CD-ROM drives are also peripherals in technical terms and are called internal peripherals, but may not be recognized as peripherals by laypeople.In a system on a chip, peripherals are incorporated into the same integrated circuit as the central processing unit. They are still referred to as "peripherals" despite being permanently attached to (and in some sense part of) their host processor.Common Peripherals
- Input
- Keyboard
- Computer mouse
- Graphic tablet
- Touchscreen
- Barcode reader
- Image scanner
- Microphone
- Webcam
- Game controller
- Light pen
- Scanner
- Digital camera
- Output
- Computer display
- Printer
- Projector
- Speaker
- Storage devices
- Floppy disk drive
- Flash drive
- Disk drive
- Smartphone or Tablet computer storage interface
- CD/DVD drive
- Input/Output
- Modem
- Network interface controller (NIC)
Input Devices
In computing, an input device is a peripheral (piece of computer hardware equipment) used to provide data and control signals to an information processing system such as a computer or other information appliance. Examples of input devices include keyboards, mice, scanners, digital cameras and joysticks.Many input devices can be classified according to:- modality of input (e.g. mechanical motion, audio, visual, etc.)
- the input is discrete (e.g. key presses) or continuous (e.g. a mouse's position, though digitized into a discrete quantity, is fast enough to be considered continuous)
- Whether the input is direct or indirect. With direct input, the input space coincides with the display space, i.e. pointing is done in the space where visual feedback or the pointer appears. Touchscreens and light pens involve direct input. Examples involving indirect input include the mouse and trackball.
- Whether the positional information is absolute (e.g. on a touch screen) or relative (e.g. with a mouse that can be lifted and repositioned)
Keyboards
A keyboard is a human interface device which is represented as a layout of buttons. Each button, or key, can be used to either input a linguistic character to a computer, or to call upon a particular function of the computer. They act as the main text entry interface for most users. Traditional keyboards use spring-based buttons, though newer variations employ virtual keys, or even projected keyboards. It is typewriter like device composed of a matrix of switches.Examples of types of keyboards include:- Keyer
- Keyboard
- Lighted Program Function Keyboard (LPFK)
Pointing Devices

Composite Devices

- Game controller
- Gamepad (or joypad)
- Paddle (game controller)
- Jog dial/shuttle (or knob)
- Wii Remote
Imaging and Input Devices

- Digital camera
- Digital camcorder
- Portable media player
- Webcam
- Microsoft Kinect Sensor
- Image scanner
- Fingerprint scanner
- Barcode reader
- 3D scanner
- Laser rangefinder
- Eye gaze tracker
- Computed tomography
- Magnetic resonance imaging
- Positron emission tomography
- Medical ultrasonography
Audio Input Devices
Audio input devices are used to capture sound. In some cases, an audio output device can be used as an input device, in order to capture produced sound.- Microphones
- MIDI keyboard or other digital musical instrument
Output Devices
An output device is any piece of computer hardware equipment used to communicate the results of data processing carried out by an information processing system (such as a computer) which converts the electronically generated information into human-readable form.[13][14]Display Devices
A display device is an output device that visually conveys text, graphics, and video information. Information shown on a display device is called soft copybecause the information exists electronically and is displayed for a temporary period of time. Display devices include CRT monitors, LCD monitors and displays, gas plasma monitors, and televisions.[15]Input/Output

Examples
These examples of output devices also include input/output devices.[17][18] Printers and visual displays are the most common type of output device for interfacing to people, but voice is becoming increasingly available.[19]- Speakers
- Headphones
- Screen (Monitor)
- Printer
- Voice output communication aid
- Automotive navigation system
- Braille embosser
- Projector
- Plotter
- Television
- Radio
Computer Memory
In computing, memory refers to the devices used to store information for use in a computer. The term primary memory is used for storage systems which function at high-speed (i.e. RAM), as a distinction from secondary memory, which provides program and data storage that is slow to access but offer higher memory capacity. If needed, primary memory can be stored in secondary memory, through a memory management technique called "virtual memory." An archaic synonym for memory is store.[20]Volatile Memory

Non-Volatile Memory

- Laplante, "Philip A. (Dec 21, 2000). \n Dictionary of Computer Science, Engineering and Technology\n . CRC Press. p. 366. ISBN 0-8493-2691-5. Retrieved June 17,2014." ↵
- "Peripheral "Definition\". Support.about.com. 2012-04-10. Retrieved 2012-11-02\n ." ↵
- "Data "Processing Concept\" (PDF). The National Institute of Open Schooling (NIOS). pp. 24-37. Retrieved 2 June 2012." ↵
- "Definition "of: output device\". Encyclopedia. The Computer Language Company Inc. Retrieved 2 June 2012." ↵
- Lemley, "Linda. \"Chapter 6: Output\". Discovering Computers. University of West Florida. Retrieved 3 June 2012." ↵
- "Data "Processing Concept\"" ↵
- "Input "devices, processing and output devices\". GCSE Bitesize. BBC. Retrieved 2 June 2012." ↵
- Kim, "Daeryong. \"Hardware Output Devices\". Fundamental Microcomputer Information Technology. The University of Mississippi. Retrieved 2 June 2012." ↵
- "Output "device\". A Dictionary of Computing. Oxford University Press. 2008. Retrieved 3 June 2012." ↵
- A.. "Turing and R.A. Brooker (1952). \n Programmer's Handbook for Manchester Electronic Computer Mark II\n . University of Manchester." ↵
- Laplante, "Philip A. (Dec 21, 2000). \n Dictionary of Computer Science, Engineering and Technology\n . CRC Press. p. 366. ISBN 0-8493-2691-5. Retrieved June 17,2014." ↵
- "Peripheral "Definition\". Support.about.com. 2012-04-10. Retrieved 2012-11-02\n ." ↵
- "Data "Processing Concept\" (PDF). The National Institute of Open Schooling (NIOS). pp. 24–37. Retrieved 2 June 2012." ↵
- "Definition "of: output device\". Encyclopedia. The Computer Language Company Inc. Retrieved 2 June 2012." ↵
- Lemley, "Linda. \"Chapter 6: Output\". Discovering Computers. University of West Florida. Retrieved 3 June 2012." ↵
- "Data "Processing Concept\"" ↵
- "Input "devices, processing and output devices\". GCSE Bitesize. BBC. Retrieved 2 June 2012." ↵
- Kim, "Daeryong. \"Hardware Output Devices\". Fundamental Microcomputer Information Technology. The University of Mississippi. Retrieved 2 June 2012." ↵
- "Output "device\". A Dictionary of Computing. Oxford University Press. 2008. Retrieved 3 June 2012." ↵
- A.. "Turing and R.A. Brooker (1952). \n Programmer's Handbook for Manchester Electronic Computer Mark II\n . University of Manchester." ↵
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