I would think the original poster has it upside-down? If you are asking what one would do with a greenhouse, you don't really need a greenhouse. If you are busting out of your seams collecting/growing plants which would never survive in your climate zone and/ or you are an avid gardner/(professional )grower and you need/wish to give your plants a head start in the Spring, you will ask for a greenhouse because you need one.
Something like that?
