Bipole: A speaker design which generates equal amounts of sound both forward and backward, with the two sounds being "in phase." Bipole speakers are often used as surround speakers when placed behind the listening area.
Dipole: A speaker design which generates equal amounts of sound both forward and backward, with the two sounds being "out of phase." Dipoles are often used as surround speakers placed to the side of the listening area.
General Features
Lets you mount the speakers to the wall with matching brackets. Note that most brackets do not include hardware to attach the bracket to the wall.
Keyhole means the speaker has a keyhole slot on the back that lets you mount it directly to the wall.