Okay, Saga,
Chant this to yourself:
The Main takes you UP TO the Wind.
The Jib takes you OFF OF the Wind.
Great exercise we used to do in the RYA Day
Skipper course is make the students steer the
boat using
sails only. Lash the tiller/rudder in the centre and manouvre **sails only** to achieve your course.
REALLY great way to viscerally understand the role of each sail and how their overlap works to drive your sailboat.
Now everybody go try it!

(Ain't she bossy)
Warmly,
LittleWing77