Are the spritz cookies the little cookies you squeeze out the piping tube thingy? If so, there definitely is a difference. The spritz cookies are lighter and crisper. Sounds like a google questions. Good luck! k
I think spritz are more like a butter cookie that you use a press for. Sugar cookies are a soft dough also that is usually refrigerated in a log and sliced.
Digit
Wanted to add this link: http://www.baking911.com/
Great site because it helps understand the reactions between ingredients and great trouble shooting tips.