Circle of Concern and Circle of Influence

Two circles, one circle of concern, and two, circle of influence. What's the difference? There's a nice little picture in the book. The small circle is circle of influence, and then around that is a bigger circle, and it sa circle of concern. I seems clear. What does it mean for us? Next part is somethin another area, something we need to think about when we are pro active. Like, how do we do it? What should we focus on? Where do we focus to get results in our life?"