this is what I got when I copied and pasted your question into google: http://answers.yahoo.com/question/index?qid=20081209062007AAeea2D
Depends what the recipe is. If it's a cake, then yes probably. If it's something else then you might want to rehydrate it (soak it in water or coconut milk), so it's a bit wetter (and make sure it's not sweetened desiccated coconut)
One is grated and the other is dessicated, obviously. Although I believe you can also get dessicated coconut cream, which is a different beast altogether. Unless of course it means coconut that you have just grated personally?
Maybe it has. Grating & desiccation are hardly mutually exclusive. Something can be grated or desiccated, or grated & desiccated, or even desiccated & grated. In answer to the OP - the difference is that you can easily rehydrate desiccated coconut, whereas it's a right old faff trying to stick a grated coconut back together. Hope that helps.