A physical device, capable of data collection or distribution. Often (but not always) a device is also intrinsically a sensor.
A component that serves as an exit from the application for data or content. The touch screen on a mobile device could be an Output, as could be a haptic feedback device.
A component that observes some aspect of the physical world and creates data. Usually associated with a device.
Represents a natural-language processing voice agent, such as Siri, Alexa, Cortina, OK Google etc.