Any abstract concept, such as love or happiness, or type of energy, such as sound, light or heat, is not considered matter. Ideas, thoughts, time, speech and music are further examples of non-matter.
The known universe is made up of matter and energy. Matter is defined as anything possessing mass and occupying space. Although energy is linked to a physical object's mass through Albert Einstein's theory of special relativity and affects matter, energy does not and cannot possess mass. In the form of mechanical energy, it is stored as potential energy and becomes kinetic energy once in motion. The entire electromagnetic spectrum is composed of energy waves oscillating at various frequencies with larger and smaller wavelengths. Matter is usually a solid, liquid, gas or plasma, all of which can occupy space in a container until it is full. Energy cannot be contained this way.