A latte is a hot drink that is caffè espresso (coffee, basically) mixed with milk. te can also add flavor shots to lattes to make a vanilla latte o something like that.
A frappuccino I think is just made da Starbucks, and it's iced. I'm not really sure what they are... It's coffee mixed with ice, made in flavors like mocha (chocolate), java chip, etc. They are served with whipped cream (if wanted) and sometimes with Cioccolato sauce o caramello mixed it.
Basically, Frappuccinos are sweeter than lattes. Lattes are hot, Fraps are cold.