We can be located on the Earth's surface thanks to coordinates measured according to a reference axis system. These are always linked to a geodesic data system.

What are called Cartesian geocentric coordinates are measured in X, Y and Z axes relative to 3 axes having their origin at the center of mass of the Earth. Geographic coordinates are indicated in the form of degrees of angles relative to a meridian (longitude) and the equator (latitude). They are expressed in degrees-minutes-seconds. It also uses the plane coordinates after applying a projection system that are expressed mostly in metric units - metres or kilometers).

See also: Latitude, Longitude, Projection (System of)
[French: Coordonnées (Système de)]