a mouse (plural mouses, mice, or mouse devices) is a pointing device that functions by detecting two-dimensional motion relative to its supporting surface. Physically, a mouse consists of an object held under one of the user's hands, with one or more buttons. It sometimes features other elements, such as "wheels", which allow the user to perform various system-dependent operations, or extra buttons or features can add more control or dimensional input. The mouse's motion typically translates into the motion of a pointer on a display , which allows for fine control of a Graphical User Interface .
a keyboard is an input device , partially modeled after the typewriter keyboard , which uses an arrangement of buttons or keys , to act as mechanical levers or electronic switches. A keyboard typically has characters engraved or printed on the keys and each press of a key typically corresponds to a single written symbol . However, to produce some symbols requires pressing and holding several keys simultaneously or in sequence. While most keyboard keys produce letters , numbers or signs ( characters ), other keys or simultaneous key presses can produce actions or computer commands.
A 3D scanner is a device that analyzes a real-world object or environment to collect data on its shape and possibly its appearance (i.e. color). The collected data can then be used to construct digital, three dimensional models useful for a wide variety of applications. These devices are used extensively by the entertainment industry in the production of movies and video games. Other common applications of this technology include industrial design, orthotics and prosthetics, reverse engineering and prototyping, quality control /inspection and documentation of cultural artifacts.
A joystick is an input device consisting of a stick that pivots on a base and reports its angle or direction to the device it is controlling. Joysticks are often used to control video games, and usually have one or more push-buttons whose state can also be read by the computer. A popular variation of the joystick used on modern video game consoles is the analog stick .
A microphone, colloquially called a mic or mike (both pronounced /ˈmaɪk/), is an acoustic-to-electric transducer or sensor that converts sound into an electrical signal . Microphones are used in many applications such as telephones , tape recorders , hearing aids , motion picture production, live and recorded audio engineering , in radio and television broadcasting and in computers for recording voice, VoIP , and for non-acoustic purposes such as ultrasonic checking.
The most common design today uses a thin membrane which vibrates in response to sound pressure. This movement is subsequently translated into an electrical signal. Most microphones in use today for audio use electromagnetic induction (dynamic microphone), capacitance change (condenser microphone, pictured right), piezoelectric generation, or light modulation to produce the signal from mechanical vibration.
A webcam is a video capture device connected to a computer or computer network , often using a USB port or, if connected to a network, ethernet or Wi-Fi .
Their most popular use is for video telephony, permitting a computer to act as a videophone or video conferencing station . Other popular uses, which include the recording of video files or even still-images, are accessible via numerous software programs, applications and devices.
They are well known for their low manufacturing costs and flexibility. 
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 ) to the outside world.
In computing, input/output , or I/O, refers to the communication between an information processing system (such as a computer ), and the outside world. Inputs are the signals or data sent to the system, and outputs are the signals or data sent by the system to the outside.
The most common input devices used by the computer are the keyboard and mouse. The keyboard allows the entry of textual information while the mouse allows the selection of a point on the screen by moving a screen cursor to the point and pressing a mouse button. The most common outputs are monitors and speakers.
Examples of output devices: Speakers Printer headphone
A monitor or display (sometimes called a visual display unit ) is a piece of electrical equipment which displays images generated by devices such as computers , without producing a permanent record. The monitor comprises the display device, circuitry , and an enclosure. The display device in modern monitors is typically a thin film transistor liquid crystal display (TFT-LCD), while older monitors use a cathode ray tube (CRT).
A Central Processing Unit ( CPU ) or processor is an electronic circuit that can execute computer programs , which are actually sets of instructions. This term has been in use in the computer industry at least since the early 1960s ( Weik 2007) . The form, design and implementation of CPUs have changed dramatically since the earliest examples, but their fundamental operation remains much the same.
a printer is a peripheral which produces a hard copy (permanent readable text and/or graphics) of documents stored in electronic form, usually on physical print media such as paper or transparencies. Many printers are primarily used as local peripherals, and are attached by a printer cable or, in most newer printers, a USB cable to a computer which serves as a document source. Some printers, commonly known as network printers, have built-in network interfaces (typically wireless and/or Ethernet), and can serve as a hardcopy device for any user on the network. Individual printers are often designed to support both local and network connected users at the same time. In addition, a few modern printers can directly interface to electronic media such as memory sticks or memory cards, or to image capture devices such as digital cameras, scanners; some printers are combined with a scanners and/or fax machines in a single unit, and can function as photocopiers.
Computer speakers, or multimedia speakers, are external speakers , commonly equipped with a low-power internal amplifier. The standard audio connection is a 3.5mm (1/8 inch) stereo jack plug often colour-coded lime green (following the PC 99 standard) for computer sound cards . A plug and socket for a two-wire (signal and ground) coaxial cable that is widely used to connect analog audio and video components. Also called a "phono connector," rows of RCA sockets are found on the backs of stereo amplifier and numerous A/V products. The prong is 1/8" thick by 5/16" long. A few use an RCA connector for input. There are also USB speakers which are powered from the 5 volts at 200 milliamps provided by the USB port, allowing about half a watt of output power.
Computer speakers range widely in quality and in price. The computer speakers typically packaged with computer systems are small plastic boxes with mediocre sound quality. Some of the slightly better computer speakers have equalization features such as bass and treble controls, improving their sound quality somewhat.
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.
USB (Universal Serial Bus) is a way of setting up communication between a computer and peripheral devices. USB is intended to replace many varieties of serial and parallel ports . USB can connect computer peripherals such as mice , keyboards , PDAs , gamepads and joysticks , scanners , digital cameras , printers , personal media players , flash drives , and external hard drives . For many of those devices, USB has become the standard connection method. USB was designed for personal computers , but it has become commonplace on other devices such as PDAs and video game consoles , and as a power cord between a device and an AC adapter plugged into a wall plug for charging. As of 2008, there are about 2 billion USB devices sold per year, and approximately 6 billion total sold to date.
The design of USB is standardized by the USB Implementers Forum (USB-IF), an industry standards body incorporating leading companies from the computer and electronics industries. Notable members have included Agere (now merged with LSI Corporation ), Apple Inc. , Hewlett-Packard , Intel , Microsoft and NEC