The keyboard has four zones, and the mouse is only one of many pointers

Open any keyboard app on your phone and it's just letters. Look down at a real keyboard and there are over a hundred keys: numbers on the side, a row of F1s across the top, arrows in a little block. Nobody designed that by accident.

Data reaches the computer in two ways: directly, straight from typing at the keyboard, or indirectly, after some intermediate handling — like a bar code read by a scanner. Keyboards and pointing devices are the direct route: the first general type of input hardware.