This is the difference between permission and guarantee. When an action is permitted, the right of a person to engage in it without punishment is guaranteed. When an action is guaranteed, other people can be punished for not assisting a person to do the action.
I usually notice this in regard to education. A lot of people seem to think that everyone is entitled to an education. A lot of other people think that everyone is entitled to the opportunity for an education. In the latter case, pursuit of an education is permitted to all; in the former, an obligation falls upon others to assist the pursuer of the education, with the threat of punishment if they do not.
I am permitted to smoke cigarettes. This is a freedom because it is negative. I am allowed to do the action without someone stopping me.
I am not guaranteed the right to smoke cigarettes. This would be a privilege because others would be obliged to help me or else face punishments.
It is easy logically to permit almost any behavior, because to deny permission would require a demonstration that it inhibits the same or other freedoms of another. To guarantee behavior is always an act of force (vis or violence), because it compels an action in another person.