Let's pick your role as a son/daughter, friend, and pupil.
When you're at home with your parents and talk to them, do chores, eat breakfast together, etc. you're playing the role of a son or daughter.
When you're hanging out with your friends, doing random stuf, having a good time, your're assuming your role as a friend.
When you're at school, studying, attending a lecture and listening to your teacher, you're assuming your role as a pupil.