A star system is the region that encompasses a star that includes bodies that are tied to the star through gravity. This includes, planets, planetoids, asteroid belts and other stars. The term planetary system is often used to indicate a star that is orbited by at least one planet.
This region was split into three broad zones. The hot zone is the region close to the star and is often too hot to allow for life. The Ecosphere is a region that was favourable for life as it was not too close to the star to suffer from the heat or too far away that it would be too cold. Class M planets were mostly found in this region. The cold zone was the outer edge that was far from the star. At the edge of this was the Oort cloud, which marked the boundary of a system.