We use
will1. to make a prediction.
- I think the black horse will win.
2. To talk about future facts.
- The sun will rise tomorrow.
3. For instant (spontaneous) desicions.
- I will have the chicken soup, please.
4. To make promises.
- I will bring you a present back from Berlin.
5. To offer to do something for someone.
- I will help you with that.