What's the difference between gps and wifi on a mobile phone?

I'm trying to decide whether to purchase the blackberry 8120 (which has wifi) or wait for the 8130 (GPS)?

What is the difference though? I am aware what wifi is but what exactly does GPS do?

Thanks alot.

wifi is wireless connection you can connect to wifi hotspots or other peoples computers some though reqire permission gps is global positioned sattelite which is for navigation and then there is gprs which is general radio packet data

Wi-fi is just for internet access. GPS gives you things like turn-by-turn directions and local points of interest (similar to a Garmin or Tom-Tom device for your car.) There is usually an extra fee for using the GPS service.