In my area, solid, fireproof doors are required, must swing inward towards garage, must have self closer on it. As said before, it all depends on the codes in your area.
At a minimum you will need a 20 minute metal fire rated door without glass.
Fires do start in garages and you want to keep it contained in that area until the fire department arrives. I've seen houses burn to the ground from fires that started in the garage.
Can't really add to the above, except to point out one other thing, security. In my line of work, I've seen some really creative ways of easily getting beyond a garage door.
Where I am, you need a fire rated door (not sure time limit) that self closes, but mine opens inward. to the house. I would never buy a metal door, if I could afford a fiberglass or other material and it was allowed.