Windward and Leeward
A) Windward is the side facing the wind.
Leeward is the side away from the wind.
B) Luffing; To steer closer to the wind by tilting the rig backwards.
C) Bearing off; To steer away from the wind by tilting the mast forward.
Sailable courses
D) Sailing upwind; It is impossible to sail directly against the wind direction. The closest angle on a sailboard is approx. 45 degrees. Consequently you will have to work your way to windward by tacking.
It is called sailing a beat, or upwind.
E) Sailing downwind; You are sailing with the wind in from behind.
F) Reaching; You are sailing with the wind in from the side.