"Spoilers differ from airbrakes in that airbrakes are designed to increase
drag while making little change to lift, while spoilers
greatly reduce lift while making only a moderate increase in drag."
what does the typical sailplane have? Spoilers or airbrakes?
- John "67" DeRosa

A spoiler would be a flap on the top of the wing front hinged forward of the
COP (centre-of-pressure)
such that the when it opens at the free end the airflow across the wing is
spoiled (and hence the lifting action decreased) but not
directly blocked (or braked).

A brake would be a paddle that operates at a right angle to the airflow and
directly blocks the airflow - effectively slowing the movement
of the wing relative to the airflow.

Sort of visualise the difference between a wing (spoiler) on a racing car
creating downpressure and throwing a dirty great parachute out the back to
assist braking?

Jim.