Answer:

Circles on the Earth’s surface with their centers on the line joining the north and south poles are called circles of latitude. Lines of Latitude are the horizontal lines running east-to-west on maps. All these circles are in planes parallel to the plane containing the equator. They are sometimes referred to as parallels of latitudes.

London is said to be at latitude 52° north. Sydney, Australia, has a latitude of about 34° south.