I would assume it's a powered subwoofer, so the active inputs would be using the sub's amplifer and power source, as opposed to the passive using an external amplifier or receiver.
The "active" input on your bass amp is for a bass with active pickups, i.e. one with an on-board pre-amp (usually powered by a 9V battery). The passive input is for a bass without active pickups, called "passive" pickups.
yes because i heard active pick-ups must be battery powered. i want to get a strat replacement set of emg's, but it says they are passive guitar pick-ups and i dont know how that is different from passive in sound quality. A also dont know if i want to hassle with a battery. do they have toi have batteries? how do they sound when compared to passive?