spoilers & "sport"

I just purchased a 2002 Windstar SE - a "sport" model. I understand Ford doesn't make this model anymore. What differentiates "sport" from any other Windstar? They look much the same to me.
Also, it has a spoiler. I don't want to sound totally clueless, but what function does a spoiler on a Windstar have? I've heard differing opinions from stability to keeping the rear window clean. What's the real story??
No doubt to all you van savvy experts, this is 'newbie' stuff . . . but you're the ones who would have the answers!
Thanx for any info.