At the heart of everything a computer does is a simple code that lets computers convert words, numbers, and even pictures into a string of electric pulses. This code is called binary.
To see how binary works, imagine a pair of sneaky spies on opposite sides of the city. Each spy has a code book. And each has a flashlight.
Spy Bob needs to send a message to spy Alice: “Wednesday.” But how can he do that using just light on and light off?
Luckily, each spy
