thanks that cleared up a lot of thingsYou don't have to have a light for your gecko unless you have a bioactive setup or just want them for looks. A heat emitter can be used to warm the enclosure along with an under tank heater.
Leopard geckos are nocturnal, so the light is for you. Just make sure you research the temp and vitamin needs.I am about to get a new leopard gecko and i have a tank for him but i dont know if i need a special light bulb just for him above his tank or the light in my room is enough for him