Passive vs. Active Speakers

The vast majority of speakers are passive. A passive speaker does not have a built-in amplifier; it needs to be connected to your amplifier through speaker wire. 

Active speakers, have a built-in amplifier and are fed by a low-level (line-level) signal, passed along a cable. Because the amplifier is an active electronic device, it needs power, and so you have to put any active speakers near a power outlet.

Active Speakers:
POWERED SPEAKERS
SUBWOOFERS
MUSIC SYSTEMS

Passive Speakers:
HOME THEATER SYSTEMS
FLOORSTANDING SPEAKERS
BOOKSHELF, SURROUND, AND BIPOLAR SPEAKERS
CENTER CHANNEL SPEAKERS