Output devices are pieces of computer hardware that allow a computer system to communicate information to a user or another system. This information can be in any format and includes sounds, images, and even tactile experiences. Output devices can generally only be used to send data from the computer; elements called input devices allow users and other systems to send data to the computer.
A projector is an output device.
Some of the most common output devices allow computers to present information visually. The display unit called a monitor that is attached to almost all personal computers is the best example of this. Text, photos, and other images are displayed on the monitor, allowing users to interact with computer programs and receive data. Video projectors are another type of output device. They work similarly to monitors, but display images over a much larger area. Computer printers are another type of output device that can be found easily. Printers allow the computer to produce documents, photos, and images on paper using inks and other dyes.
Braille displays allow computers to send information through raised dots that are “read” with the tips of the fingers.
Audio output devices are also common. Computer speakers are the main source of this form of output. They allow the computer to output sounds including music, audio tracks from digitized television shows, and even the voices of other users. Headphones also do the same thing, but are placed closer to the ears so that sounds cannot be heard by others.
Computers can even communicate with users through touch. Refreshable Braille displays, or Braille terminals, allow computers to send information through raised dots that are “read” with fingertips. Force feedback devices, or touch devices, are sometimes built into joysticks and mice so users can feel vibrations and pressure. Touch output devices are less common than many other types, but they can still be extremely important to users.
In rare cases, output devices can also be input devices. A storage device like a CD-RW drive is an excellent example of this. It is used by the computer as an output device when writing information to a CD-ROM or other media that other computers can read. However, the computer uses it as an input device when reading information from a CD-ROM or other storage medium that contains recorded data from another system.
Computers use input devices to read information from CD-ROMs.
