Input Device Definition

An input device is a piece of computer hardware equipment used to provide data and control signals to an information processing system, such as a computer or information appliance. Examples include keyboards, mice, and scanners.

Analyzing Computer Peripherals

Let's examine each option to determine its function:

• Trackball: This is a pointing device, functioning similarly to a mouse. It is used to input movement commands. Therefore, it is an input device.
• Light Pen: This is a light-sensitive pointing device used to select objects on a display screen. It provides input by detecting light. Therefore, it is an input device.
• Scanner: This device captures images from physical documents or objects and converts them into digital data that the computer can process. Therefore, it is an input device.
• Plotter: This device creates vector graphics on paper or other media using a pen or pencil. It produces a physical output from digital data. Therefore, it is an output device.

Conclusion: Identifying the Non-Input Device

Based on the analysis, the Trackball, Light Pen, and Scanner are all used to send information to the computer, making them input devices. The Plotter, however, is used to create a physical representation from the computer's data, classifying it as an output device.

Therefore, the Plotter is not an example of an input device.