A mechanical or electronic device that displays the time.
Thermometer
a device that displays words for people to read
monitor
monitor
an oscilloscope
Input Device
It is both. You input a problem and it displays the answer.
A real time analyzer is a professional audio device that measures and displays the frequency spectrum of an audio signal. It is a spectrum analyzer that works in real time.
It displays picture and images in real time, allowing one to interact with the computer, activating and running its programs at will. It is an output device.
An output device, such as a monitor (screen), or a printer.
When i did I.T. we always described monitors as output device not an input device. as it can not send information to the pc it only displays.