[1][2][3] A free good is available in as great a quantity as desired with zero opportunity cost to society.
For example, a shop might give away its stock in its promotion, but producing these goods would still have required the use of scarce resources.
Earlier schools of economic thought stated that resources that are enough for everyone to have as much as they want are free goods.
Thus these laws are used to give exclusive rights to the creators, in order to encourage resources to be appropriately allocated to these activities.
Futurists like Jeremy Rifkin theorize that advanced nanotechnology with the ability to turn any kind of material automatically into any other combination of equal mass will make all goods essentially free goods, since all raw materials and manufacturing time will become perfectly interchangeable.