What type of device is classified as an infrared input device?

An infrared input device is one that uses infrared signals to interact with a computer or another device. In this context, a mouse that operates using infrared signals falls squarely within this category. This type of mouse transmits its position and clicks through infrared light, allowing it to communicate wirelessly with the computer.

The other choices do not meet the criteria for an input device. For instance, a printer that uses infrared technology is designed for output, not input. Similarly, a camera that captures infrared images serves to capture visuals rather than providing input to a system. Lastly, a monitor that displays infrared light is involved in the output process. Thus, the infrared mouse is the correct choice as it fulfills the role of an input device utilizing infrared technology.