pickup question

[ubiquitos]

what is an active pickup. for example i was looking at a guitar and the description said "w/ active EMG 81's"
.... and also whats the difference between emg type pickups and humbucking pickups?

 

[Indiooo]

Active pickups have an internal preamp that needs a battery. EMG is know for active pickups, single coils and humbuckers.