From Atomic Habits

The main components of habit formation:

 • A Cue: It causes your brain to begin a behavior. It is a bit of information that predicts a reward.

 • A Craving: It is the motivation behind every habit. Without a desire, we don't have a reason to act.

 • A Response: This is the very habit you perform; it can take the form of a thought or an action.

 • A Reward: The end goal of every habit