Actually it is a process where this two is involved. When a person want to invest and does not have enough money, he tends to save for it. So the process is to save from income until he meet the needed amount. After meeting the needed amount, he then invest it to the venture he needed. This is the reason why people is saving. That at the end of the day they can invest to some venture and earn more money.
Exactly, most of the times the capital someone needs for investing is accumulated by saving, because not everyone earns enough to invest them directly to a place which can generate him some good profits so the first step of investments is saving itself.