On the Earth, a circle of latitude or parallel is an imaginary east-west circle that connects all locations with a given latitude.
The position on the circle of latitude is given by the longitude.
Each is perpendicular to all meridians at the intersection points.
Those parallels closer to the poles are smaller than those at or near the Equator.
For a low latitude a circle of latitude can be said to be a line around the Earth, while at a high latitude it is a circle around a pole.
Circles of latitude are often used as boundaries between countries or regions.
The five major circles of latitude are, starting from the North Pole and finishing at the South Pole; the Arctic Circle, the Tropic of Cancer, the Equator, the Tropic of Capricorn and the Antarctic Circle.