When you buy a mouse for your computer, removing the packaging is probably the hardest part of integrating it into your home system. Once you plug in the USB cable, you click on the mouse, and it just works. For it to "just work," of course, a great many things have to happen in the background: Via the USB cable, the mouse's circuitry receives power, initializes, and is recognized by the computer as a valid device. Then the driver software takes over, identifying the device as a mouse and not, say, a printer or a keyboard. Finally, a rapid succession of electrical messages traverses the cable, and these messages are translated into commands that then move the cursor smoothly across your computer screen. The fact that you don't need to know any of this to operate a mouse is by design: The mouse's computer chips and embedded software conceal the device's complexity.