Active fun engages your brain with problem solving (puzzles) or it develops a talent like drawing or a skill like skateboarding. it involves your muscles and your intellect. It requires you to focus, to be present and to think. It involves achievement and with group activities, cooperation.
Passive fun is where you are being entertained. Someone else is creating the fun and you are just watching. ie sports, movies, or surfing the internet. You aren’t required to have skill or to participate or to engage any mental faculties at all. All you are have to do is observe.
Sometimes you need to completely disengage and just passively be entertained, but I think we could all add more active, creative fun into our lives and still feel refreshed and rejuvenated afterwards.