Stefan outs the analogy of the distinction between Choreography and Orchestration. I first heard this along with another analogy relating to a musical score from Steve Ross-Talbot in his lightning talk "I'll name that tune in ..". I came up with another analogy, which i'm not sure is any better, but here goes:

Orchestration is akin to traffic lights where events are controlled centrally, whereas Choreography is more like a roundabout, where each participant is following a prearranged set of rules.

Update:
#1 it's Stefan, not 'Steve', d'oh!
#2 Jacek points out that a choreography is far more open ended than orchestration. Participants are encouraged to improvise, if you will.