What Is Free Will?
This is a deep topic that could take us down thousands of scientific rabbit holes without even trying too hard to do so. The real issue is that it can take us down two different roads: Hard Science and Soft Science. Hard science is stuff like chemistry, biology, etc. Meanwhile, Soft Science is stuff like sociology, anthropology, philosophy, etc. When you ask about “free will,” both sides of the scientific community will have their thoughts on the matter. They will not completely agree if they even agree slightly.
When you look at it on one side, free will is simply the idea that man can choose the path he walks. He will make the decision to do what he wants. Yet others might say that he does not because his life forces him to do similar things daily, such as go to work, eat, etc. In essence, he does not have complete free will there. If he chose to do something different, he displays free will. Meanwhile, if there is such a thing as intelligent design, nothing he does is ever free. As his actions were already decided.