A habit is comprised of three parts: a cue, a routine, and a reward. The cue is the prompt, something that triggers you to do a routine. The routine is the behavior we commonly think of as the habit. And the reward is the payoff, the satisfaction we get from meeting some craving or need. These three components, when put together, are called The Habit Loop. And every habit follows it: cue, routine, reward; cue, routine, reward.