Digital camera

Digital camera

A digital camera is a camera that takes video or still photographs by recording images on an electronic image sensor.

Digital and film cameras share an optical system, typically using a lens with a variable diaphragm to focus light onto an image pick up device. The diaphragm and shutter admit the correct amount of light to the image, just as with film but the image pick up device is electronic rather than chemical. However, unlike film cameras, digital cameras can display images on a screen immediately after being recorded, and store and delete images from memory. Many digital cameras can also record moving video with sound. Some digital cameras can crop and stitch pictures and perform other elementary image editing.

Printer

Printer

Printer is an output device that produces text and graphics on a physical medium such as paper or transparency film.

Printed information, is called hard copy, exists physically and is a more permanent form of output than that presented on a display device.

Speakers

Speakers

Computer speakers range widely in quality and in price. The computer speakers typically packaged with computer systems are small, plastic, and have mediocre sound quality. Some computer speakers have equalization features such as bass and treble controls.

The internal amplifiers require an external power source, usually an AC adapter. More sophisticated computer speakers can have a subwoofer unit, to enhance bass output, and these units usually include the power amplifiers both for the bass speaker, and the small satellite speakers.

For some users, a lead connecting computer sound output to an existing stereo system is practical. This normally yields much better results than small low-cost computer speakers. Computer speakers can also serve as an economy amplifier for MP3 player use for those who wish to not use headphones, although some models of computer speakers have headphone jacks of their own.

headphone&earbuds

Headphone&Earbuds

Headphones are a pair of small loudspeakers that are designed to be held in place close to a user's ears. Headphones either have wires for connection to a signal source such as an audio amplifier, radio, CD player, portable media player or mobile phone, or have a wireless receiver, which is used to pick up signal without using a cable. They are sometimes known as ear speakers or, colloquially, cans.

The in-ear versions are also known as earphones or earbuds. In the context of telecommunication, a headset is a combination of headphone and microphone.

Touch screen

Touch screen

A touch screen is an electronic visual display that the user can control through simple or multi-touch gestures by touching the screen with one or more fingers. Some touch screens can also detect objects such as a stylus or ordinary or specially coated gloves. The user can use the touch screen to react to what is displayed and to control how it is displayed (for example by zooming the text size).

The popularity of smartphones, tablets, and many types of information appliances is driving the demand and acceptance of common touch screens for portable and functional electronics. Touch screens are popular in the medical field and in heavy industry, as well as in kiosks such as museum displays or room automation, where keyboard and mouse systems do not allow a suitably intuitive, rapid, or accurate interaction by the user with the display's content.

Pen input

Pen input 

Pen input refers to a computer user-interface using a pen (or stylus), rather than devices such as a keyboard, joysticks or a mouse.

Pen input is also used to refer to the usage of mobile devices such as wireless tablet personal computers, PDAs and GPS receivers. The term has been used to refer to the usage of any product allowing for mobile communication. An indication of such a device is a stylus, generally used to press upon a graphics tablet or touch screen.

Game controller

Game controller

A game controller is a device used with games or entertainment systems to provide input to a video game, typically to control an object or character in the game. A controller is usually connected to a game console or computer by means of a wire or cord, although wireless controllers are also widespread. Input devices that have been classified as game controllers include keyboards, mice, game pads, joysticks, etc. Special purpose devices, such as steering wheels for driving games and light guns for shooting games, are also game controllers.