Basic Concepts of Navigation

Latitude
The latitude of a place on the earth's surface is the angular distance north or south of the [equator]. Latitude is usually expressed in [degree (angle)degrees]] (marked with °) ranging from 0° at the Equator to 90° at the North and South poles. The latitude of the North Pole is 90° N, and the latitude of the South Pole is 90° S. Longitude
Similar to latitude, the longitude of a place on the earth's surface is the angular distance east or west of the prime meridian or Greenwich meridian.. Longitude is usually expressed in degrees (marked with °) ranging from 0° at the Greenwich meridian to 180° east and west. Sydney, Australia, for example, has a longitude of about 151° east. New York City has a longitude of about 74° west.