If you think of the CPU as a computer’s brain, then you might think of
the input devices as its sensory organs—the eyes, ears, and fingers.
From the user’s point of view, input devices are just as important as the
CPU, perhaps even more important. After you buy and set up the computer, you may take the CPU for granted because you interact directly
with input devices and only indirectly with the CPU. But your ability to
use input devices is critical to your overall success with the whole
An input device does exactly what its name suggests: it enables you
to enter information and commands into the computer. The most commonly used input devices are the keyboard and the mouse. If you buy a
new personal computer today, it will include a keyboard and mouse unless you specify otherwise. Other types of input devices arc available as
well, such as variations of the mouse and specialized "alternative" input
devices such as microphones and scanners.
This chapter introduces you to the keyboard and the mouse. You will
learn the importance of these devices, the way the computer accepts
input from them, and the many tasks they enable you to perform on