A program is a single action or set of actions intended to influence something outside itself. A system is a set of interrelating parts that performs functions inside itself. It is a set of ideas or objects that must work together to perform a particular function.
Programs are simple and direct.
Politicians like them because they appear to be serious, tough, decisive, and sound-bitable. Systems are complex and indirect. For example, under a crime prevention program , crime might be stopped by enforcement agents that intervene directly, at a cost to taxpayers. Under a crime prevention system , crime might be reduced automatically, as a byproduct of another action a system of potential penalties, or perhaps a public education system that provides better opportunities reducing crime because people have less desire to commit it. Similarly, under a forest protection program , deforestation might be stopped by hiring police to arrest violators, or land might be purchased to take it out of the marketplace.