How do sails on a sail boat work?

Answer:
Sails catch the wind which propels the boat forward

2nd Answereer says:
Previous answerer has been tricked by a trick question:
IN REALITY the wind foils around the the sail and PULLS the boat forward. A sail is nothing more than a vertical wing, providing LIFT. Should you ever have the pleasure to experience a strong puff of wind startling your becalmed craft, you will FEEL the LIFT that is provided. It's a physics thing (Aerodynamics).
First answer by ID1280262494. Last edit by LeastDuck. Contributor trust: 691 [recommend contributor recommended]. Question popularity: 2 [recommend question].