Laws of conservation

Many of the regularities (or symmetries) observed in science may be expressed as the laws of conservation, each of which states that a particular measurable property (or quantity) of an isolated physical system does not change (i.e., is constant) during the course of time. These laws are perhaps the most powerful tools of analysis in physics.

Another important function of the laws of conservation is that they make possible the prediction of the macroscopic behavior of a system without necessarily delving into the microscopic details of the system and its behavior.

There are a good many laws of conservation. For example, there are the conservation of mass, conservation of energy, conservation of momentum and conservation of charge.