The northern boundary of the Torrid Zone is the Tropic of Cancer and its southern boundary is the Tropic of Capricorn. The Torrid Zone, also known as the Tropical Zone, is the region of perpetual summer. It also contains the tropical rain belt, which runs along the equator and stretches north and south to the Torrid Zone's boundaries.
The Torrid Zone is one of the five main geographic regions of the Earth's surface. The difference between the regions relates to climate and they are defined by the major circles of latitude. The Torrid Zone is the centermost of the five regions. The two regions above it are the North Frigid Zone, which is north of the Arctic Circle, and the North Temperate Zone, which lies between the Arctic Circle and the Tropic of Cancer. Below the Torrid Zone is the South Temperate Zone, which stretches down from the Tropic of Capricorn to the Antarctic Circle, and the South Frigid Zone, which is the region south of the Antarctic Circle.