What type of input device is a touchscreen?

A touchscreen is considered both an input and output device because it serves multiple functions. As an input device, a touchscreen allows users to interact directly with what is displayed on the screen by touching it with their fingers or a stylus. This interaction enables users to select options, enter data, and navigate through applications, making it a primary means of inputting information into a system.

Simultaneously, a touchscreen is also an output device because it displays visual content such as images, text, videos, and graphics. It provides feedback to the users by visually representing the information that they can interact with. This dual functionality makes touchscreens versatile and widely used in various devices, including smartphones, tablets, and some computer monitors.

The other choices fail to capture this dual role: labeling the touchscreen as only an input device overlooks its ability to display information, while categorizing it as an output device ignores its role in user interaction. Considering it "not a device" dismisses its fundamental existence and functionality in modern technology. Therefore, defining a touchscreen as both an input and output device accurately reflects its comprehensive role in user interaction and information presentation.