There is a difference.

Many people who are not physical educated try to use the phrases physical activity and physical education interchangeable. This is incorrect, because they are not the same, they mean different things. To clear this up, physical activity is a behavior. For example walking, running, swimming, biking, playing a sport. These are all forms of physical activity. On the other hand physical education is the school program that is designed to lead children to a life time of physical activity. Where I believe the confusion come into play with these two phrases is the fact that physical education uses and embraces physical activity.