When you roll Initiative, you can regain all expended Focus Points. When you do so, roll your Martial Arts die, and regain a number of Hit Points equal to your Monk level plus the number rolled.
Once you use this feature, you can’t use it again until you finish a Long Rest.
Your Monk level determines the number of points you have, as shown in the Focus Points column of the Monk Features table.
You can expend these points to enhance or fuel certain Monk features. You start knowing three such features: Flurry of Blows, Patient Defense, Step of the Wind.
Flurry of Blows: You can expend 1 Focus Point to make two Unarmed Strikes as a Bonus Action.
Patient Defense: You can take the Disengage action as a Bonus Action. Alternatively, you can expend 1 Focus Point to take both the Disengage and the Dodge actions as a Bonus Action.
Step of the Wind: You can take the Dash action as a Bonus Action. Alternatively, you can expend 1 Focus Point to take both the Disengage and Dash actions as a Bonus Action, and your jump distance is doubled for the turn.