Philosophers are funny. They will arbitrarily decide that a word has a particular definition and stick to that definition for a whole conversation. For example, they might decide that"hat" means "the color blue" and proceed to have a whole conversation about hats. It's a thing they do.
If you pay attention when they talk about free will, you will notice that philosophers will subtly change the definition of the word in the middle of a conversation without warning. If you can't pin a philosopher down to one definition for the topic of discussion for the whole discussion, then I just don't see how you're going to get a useful discussion with anyone else on that topic because we are going to be even more likely to switch definitions without warning, mucking up the meaning of whatever we're talking about. Discussions about free will most likely are not useful nor meaningful. I'm going to talk about it anyway.
Free Will: Philosophical vs Colloquial Definition
When philosophers and regular people talk about free will, they're talking about two different things. For ordinary people, free will means "the ability to make decisions." If you are one of those people who defines free will that way, then you can relax and stop reading right here. You have the ability to make decisions with or without free will, so you can simply ignore everything the eggheads have to say about free will.
If you don't understand how decisions can be made without free will, take a programming class. You will see how easy it is to create something that makes decisions in response to the real world, and you will notice that you did nothing to give the program free will before shoving the text into a compiler. Programs can make decisions based on what happens in the real world, and as anyone who has been a victim of a computer error at their bank can tell you, programs make decisions that in turn affect the real world.
Determinism
What the eggheads mean centers around the concept of determinism. Let's imagine that I made a perfect copy of you at a particular moment in time down to the last atom. Not only does this copy of you have all the same atoms in all the same places, but all of those atoms have the same relative velocities (direction and speed) as the corresponding atoms in your body at that particular time.
Now let's say we swap that copy in for you at the exact time in question. What do you think will happen?
If you are a determinist, then you believe that the copy will make all the same decisions that you would have made. If you believe in the philosophical concept of free will, then you believe that the copy will make entirely different decisions even though it has all the same atoms in its brain because the copy will not have the same magical invisible spirit (soul) making the decisions.
I studied physics in college, but I'm not going to claim to be a physicist by any stretch of the imagination, but I do understand enough to know that a macroscopic brain made up of trillions of atoms is going to be governed by deterministic forces and that the copy will make all the same decisions, and this is the answer most physicists and neuroscientists will give you on this topic. You see, both physics and neuroscience is starting to encroach on what used to be the sole domain of philosophers, and the philosophers are not happy about this encroachment, particularly given that physics is also encroaching on their domain on the topic of what "nothingness" is or is not.
Quantum Physics and Free Will
This is where quantum physics enters the picture. It seems to be the go-to excuse for people pushing supernatural quackery, and people who believe in the philosophical notion of free will are no different from those new-age nutbars who want to believe that all sentient beings have superpowers.
The argument goes like this: some kind of quantum effect influences decisions made by the human brain, kind of like the petri dish with poison in the Schrödinger's cat thought experiment, therefore the human brain is not deterministic, therefore free will is a thing.
Go ahead. Conduct an experiment showing that subatomic quantum events influence the decisions made by human beings. This part is funny because the people proposing this cannot even identify a functional mechanism by which this could theoretically happen, much less propose an experiment to actually prove it. Of course, these are philosophers, so they're not going to do that because philosophers are allergic to evidence.
Not that it matters. Let's say for the sake of argument that this is true: some quantum event affects the decisions we make. After all, isn't that what philosophers do? If this is true, then the human brain is nothing more than a quantum slot machine making decisions at random in response to subatomic events. This may satisfy what philosophers mean by free will, but this definitely is not what regular people mean by free will.
Conclusion: It Doesn't Matter
In the end, it doesn't really matter to ordinary folk. As I mentioned before, to most ordinary people, "free will" just means the ability to make decisions, and you don't need free will for that. Even if determinism is true, then the time and effort you put into considering a decision before making it is one of the deterministic effects that influence the final decision.
Considering a decision before making it matters regardless of whether or not the free will proponents or the determinists are right. At the end of the day, "free will" is just a noise theologians make when they cannot resolve a logical contradiction created by their own claims. For ordinary people, none of this discussion about free will actually means very much.