Can someone explain a little about the different lighting

[lil.guppy]

Why is it that I see some nanos with lighting as if it was freshwater and others where the lights are hovering over the tank.
I really dont like the hover look and was wondering if I can just use my freshwater hood? Its those plastic ones with the 2 bulb insert.

 

[TimSchmidt]

If you don't want coral you can use any light you want. If you want photosynthetic inhabitants (coral) then you will need to read up a bit on either compact florescent, T5, Metal Halide, or high output florescent lighting.