Tech moves fast! Stay ahead of the curve with Techopedia!
Join nearly 200,000 subscribers who receive actionable tech insights from Techopedia.
An output device is any hardware device used to send data from a computer to another device or user.
Usually, most output peripherals are meant for human use, so they receive the processed data from the computer and transform it in the form of audio, video, or physical reproductions.
Typical examples of output devices are monitors and projectors (video), headphones and speakers (audio), or printers and plotters (physical reproduction in the form of text or graphics).
Output devices allow computers to communicate with users and with other devices.
This can include peripherals, which may be used for input/output (I/O) purposes, like network interface cards (NICs), modems, IR ports, RFID systems and wireless networking devices, as well as mechanical output devices, like solenoids, motors and other electromechanical devices.
Unlike input devices, output devices are not strictly necessary for a computer to operate.
However, without them the purpose of a computer may be defeated since there’s no way of determining how the data is currently processed or what the system is doing.
For example: if you click “play” on a YouTube video and then plug your monitor off, the computer will keep reproducing it and, provided the speakers are turned on, the audio output will be guaranteed.
In fact, the computer will still consume all the resources and process the data required to run the video regardless of the presence of the output device (the monitor).
In order to work, an output device needs to receive a signal from the computer after the information it has processed is ready to be displayed into its new format (e.g. audio or video).
The process usually follows certain steps:
A signal is sent from an input device to the computer (e.g. the user clicks with the mouse on the “play” button of a video).
The computer processes the input and then sends a new signal to the output device (e.g. the monitor and speakers).
The output devices receive the signal and display the output (e.g. the monitor shows the video, and the speakers run the audio signal).
Additional steps can be taken to let other output devices process this same signal.
For example: the user could click the “Print Screen” button on his keyword (input device) to request the printer (output device) to print a screenshot of that video.
Note that the other output device (the monitor) is not required to process this signal, so even if the monitor was turned off, the printer will still be able to print that screenshot even if the user couldn’t see it.
Other more or less common output devices include speech-generating devices that transform plain text into audible sounds, and GPS devices that process satellite geolocation signals to calculate position and time.