It's just the next version of the android OS that is 2.2. When the EVO first rolled out it had android OS 2.1(eclair). Its just a new version of the OS. There's no such thing as a dumb question, everyone starts at different level.
I have nothing useful to add that hasn't been already said but I will say this: Since I got Froyo I've started buying frozen yogurt. Yup, I'm a geek...