The sun is not a living thing. It is made up of gases, such as hydrogen and helium, rather than living cells, which are present in all forms of life. Science defines living things as having seven basic characteristics, and the sun has none of these characteristics.
Living things must be composed of a one or more cells. Living things must have different levels of organization, such as molecular and cellular organization and the ability to organize simple substances into complex ones within themselves. Living things also use energy, grow, reproduce, adapt to their environment and respond to their environment.