A Level 2 driving aid that needs a driver to watch and take over.
FSD is like a very eager co-driver. It can steer and brake. You still keep your hands ready. No nap time.
It can help with routes, lane changes, and parking. Features vary by car, place, and software version.
L2 vs L4 Autonomous Driving
FSD is Level 2 driving help. The driver must watch it and take over anytime.
Driving AI
FSD puts driving help into regular Tesla cars.