"Outer" is a term that can refer to something that is situated on the outside or exterior of an object or area. It is often used to describe layers, surfaces, or regions that are not part of the inner core. For example, the outer layer of the Earth consists of the crust, which is the surface we live on. In a broader context, "Outer" can also relate to concepts such as outer space, which refers to the vast expanse beyond Earth's atmosphere. This area is home to celestial bodies like stars, planets, and galaxies, and is studied in fields like astronomy and astrophysics.