The geographical coordinates are two: the latitude and the longitude. They determine the exact position of places and navigable means on the Earth’s surface. The network of geographical coordinates on the elliptic or on the sphere is a network of meridians and parallels. Is, in fact, a system of surface coordinates and presents in two dimensions the general plan of large areas even the general plan of the earth.

Latitude

Is the arc of the meridian of a given place that is intersected between the equator and the place. It is counted from 0- 90 degrees and it is North or South if it is situated in the North or South hemisphere respectively.

Longitude

Is the arc of the earth’s equator intersected between the meridian of a given place and the prime meridian and is expressed either in degrees or in time. It is counted from 0- 180 degrees and it is North or West if it is situated right or left of Greenwich respectively.