The habitable zone, also known as the circumstellar habitable region or simply the habitable zone, is a term used in astronomy and exoplanet research to describe the area around a star where conditions might be suitable for life. This means that it is an area where liquid water could exist on the surface of a planet, given certain atmospheric conditions such as temperature and pressure. The size and location of this habitable zone depends on several factors including the type and age of the host star, its mass, luminosity, and spectral class. In our solar system, for example, the habitable zone is located between Mars and Jupiter, where Earth resides. So when someone refers to their "habitable zone" they are referring to the area around their host star that has conditions suitable for life as we know it.