Physics is the science of nature in the broadest sense. Physicists study the behaviour and interactions of matter and energy, which are referred to as physical phenomena. Physics is the study of matter, energy, motion, and forces. Physics is a major branch of science, concerned with the fundamental components of the universe, the forces they exert on one another, and the results produced by these forces.

Physicists study the properties and forms of matter and energy - heat, light, electricity and magnetism, and nuclear energy. They try to understand the forces that act in the universe, and the laws that these forces obey - e.g. matter and energy can't be destroyed, only changed from one to the other (a conservation law).