Physics is the science that studies nature in its broadest sense, dealing with the behavior of matter and energy, and the fundamental forces of nature that govern interactions between particles.
Discoveries in physics find application in all other natural sciences, as matter and energy are the basic components of the natural world. Some of the properties studied in physics are common to all material systems, such as the conservation of energy. These properties are often referred to as physical laws. It is sometimes said that physics is the fundamental science, because other sciences (biology, chemistry, geology, etc.) deal with specific types of material systems that obey the laws of physics.
Physics is closely related to mathematics; mathematics provides physics with the language and necessary tools that allow for a precise (quantitative) formulation of physical laws and the phenomena they imply. This, in turn, makes it possible to experimentally verify or discard predicted results.