active means you chose to do something, or you are aware of something, the direct definition is energetic, but i dont think we mean that here. passive means you do it without choice or it happens automatically, difinition i think says it lacks forceful qualities. active things are like choice movements, walking ect and also things like thinking, because we chose to do them. passive things are like our heartbeats because they beat automatically. however depending on the context heartbeat would be active because exerts force, infact if you really wanna think about it, very little we do is passive except for perhaps diffusion in breathing and chemical-degistive absorption. Everything we do is goverend by ATP which of course dictates active transport. It really does depend on what you mean.