If your crossover is external (ie, before the amps in the signal path), then you're actively biamping. If your crossovers are internal to the speaker, but the speaker has separate binding posts and you're using 2 separate amps (possibly with separate power supplies?) then you're passively biamping. If you're using 2 runs of wire to 4 separate binding posts, back to 2 binding posts on the amp, you're biwiring.

I am the Doctor, and THIS... is my SPOON!