Space is mostly made up of a vacuum, which is an area that is empty of matter. A vacuum is defined as a region of space that contains very little matter or no matter at all. However, space is not completely empty. It is filled with a low density of particles, including electrons, protons, and neutrons, as well as electromagnetic radiation, such as light.
There are also large structures in space, including stars, galaxies, and clusters of galaxies, which are made up of matter in the form of gas, dust, and other substances. The space between these structures is filled with a thin, low-density gas called the intergalactic medium.
