in many ways, it's like an electric light bulb;
one that has a filament with high resistance in it will not be as hot and bright and will not consume as much electricity as one that has a low resistance filament in it.

lower resistance in a wire (or a voice coil) will let pass more current.
low resistance/impedance = low Ohms
if the resistance is low, then current going through is not impeded as much as when the resistance is high.

See: http://www.blu-ray.com/community/gallery.php?member=Gelli
or: Axiom Gallery