Yes, lighting is different as Simpleman said, if you want to keep most inverts like clams, anemones and corals. To keep those photosynthetic animals, you need lighting to match the sun, which freshwater and basic tank lighting does not do. If you want to keep saltwater fish only, you won't need special lights. Or you can start keeping fish only, save up money, then transition to a reef tank when you can afford lights.
You will need a protein skimmer, which is unique to saltwater. The cheapo crap brand is SeaClone, so you can skip that :).