The original context of the concept of free will and choice was the comparison of humans to animals and natural instinct. Human were considered higher than the animals. Animal nature and their choices are preprogrammed, by the species, in the context of the environment, thereby allowing all of nature to coordinate in 3-D.
Free will allows humans more choices or options to depart from this natural integration. Human can also choose unnatural and synthetic options as well as unnatural environments. Big cities are not natural environments that are coordinated with nature. These choices are not all in our natural DNA, but have to be learned from the outside; school.
The modern tech analogy for free will and choice is done by comparing a preprogrammed computer, to a hypothetical computer that becomes conscious and self aware. The choices of the former are decided exclusively by its preprogrammed logic in the context of various circumstances. The choices of the latter can depart from this internal programming. Something about the human brain allows humans a way to depart from the natural logic circuits connected to its DNA.
The way this is possible for humans is connected to the first person observation that humans have two centers of consciousness; inner self and the ego. The inner self is natural and connected to our DNA. This is the center of consciousness that animals also have. The ego, which is quite new on the evolutionary scale; 6-10K years, is a secondary center which can depart from the preprogrammed choices of evolution. There is nothing in evolution that led to the driving of a car.
This departure is connected to learned knowledge and the inferences that the ego can make based on that learned knowledge. The ego is not fully constrained 100%, like an animal, by the natural choices of the inner self.
As an example, the fad choices called gender preference is egocentric and based on the free will of the ego. It is not connected to the inner self; natural side of humans. It is not hard for a male to learn and copy the sterotypicial behavior of a female; watch and learn from the outside. This performance this will often appear exaggerated like a an actor on a stage; drag queen. This is all connected to the will power and choice of the ego, which if performed often enough, starts to look fluid and innate. But it is all ego and not exactly from the inner self, for else it would be better integrated with nature and not trying to center stage.
The basis for free will and choice was the appearance of the secondary center of consciousness; ego. If you compare the two side of the brain, the left brain is more differential while the right brain is more spatial. These two types of neural processing is part of the dividing line between the ego and inner self. The ego attempts to differentiate itself as unique; unique actor or player, while the inner self tries to make us more 3-D homogeneous based on human nature.
In terms of a mathematical model, the spatial nature of the inner self is like a 3-D ball. This 3-D ball can be approximated with a large number of 2-D circles, all with a common center but all at different angles. The ego tends to pick a 2-D circle; cause and affect, while the inner self common to all, is the 3-D ball. Since the circle is a valid part of 3-D ball, the ego can mistake this overlap connection to the inner self as meaning the choice is 3-D, especially if it is unaware there are two centers. A gender choice can feel 3-D; integrated wholeness, while being egocentric 2-D, due to semi-consciousness.
If we go back to the computer analogy, the living computer forms a secondary center that is not part of the original programming, but rather can alter the programming to its own needs, which tend to be more short sighted. In sci fi the smart computers go too far and need to unplugged.