I feel as though I should illustrate the difference that this one single constraint can make by two examples.
The rules of Simon Says are maximally authoritarian. You must perform any action ordered, with the only restriction that the authority must say "Simon says" first. Were you forced to stay in this system, it would be the most despotic autocracy possible. But it's not. It's a silly game because you can leave at any time.
Let's flip this and imagine a room. During a specific period of time you will have absolute control over everything in this room. In this room you have total freedom. This is not even the limited freedom, the coordinated freedom, the compromising freedom of civil society. You could, without consequence, perform any action you wish in this room. You could say anything, destroy or steal any object, order any individual to perform any action, kill any person in the room with you and take anything they own. This is the sovereign freedom, the absolute freedom, of dictators and kings. The only restriction is that you are not allowed to leave the room while you have this freedom. In fact, you really only have this level of freedom because the room is actually empty other than for you. I am, of course, talking about a form of torture still common in the US: solitary confinement.