Ordinary matter, also known as baryonic matter, is the type of matter that makes up stars, planets, and living organisms. It consists primarily of atoms, which are made up of protons, neutrons, and electrons. This matter is responsible for the physical structures we see in the universe, including galaxies, solar systems, and biological life. Unlike dark matter and dark energy, which are not directly observable, ordinary matter can be detected through various methods, such as spectroscopy and particle collisions. It accounts for about 5% of the total energy density of the universe, playing a crucial role in the formation and evolution of cosmic structures.