Whatever we perceive is Matter. The whole universe is composed of matter along with two others which are called energy and life. Matter may contain energy or life or both. However, we call matter those objects which are in themselves non-living things. Matter is distinct from energy and life.

In ancient times, in India they were believed to have composed of four "elements" - earth, water, fire, sky, and air. Empedocles held that all matter is made up of four elements — earth, air, fire, and water. Leucippus and his pupil Democritus proposed an atomic basis of matter, believing that all matter is built up from tiny particles, as Maharshi Kanva of ancient India propagated. Anaxagoras, however, rejected any theory in which matter is viewed as composed of smaller constituents, whether atoms or elements, and held instead that matter is continuous throughout, being entirely of a single substance.

The work of John Dalton at the beginning of the 19th century contributed in this knowledge which eventually altered the human thought about traditional knowledge of matter. The atom is now considered the basic unit of any element, and atoms may combine chemically to form molecules, the molecule being the smallest unit of any substance that possesses the properties of that substance. An element in modern theory is any substance all of whose atoms are the same (i.e., have the same atomic number), while a compound is composed of different types of atoms together in molecules.

Further, this atom is found to have composed of electron, proton and neutron, the forms of energy and nothing else.