A system for specifying positions on the globe. North-south positions are specified in degrees of latitude, and east-west positions are specified in degrees of longitude. Geographic coordinates may be expressed either in degrees, minutes, and seconds, or in decimal degrees.

A reference system using latitude and longitude to define the locations of points on the surface of a sphere or spheroid.

The grid system of latitude and longitude.

A Geographic CS consists of a well-defined ellipsoidal datum, a Prime Meridian, and an angular unit, allowing the assignment of a Latitude-Longitude (and optionally, geodetic height) vector to a location on earth.

A geographic coordinate system expresses every location on Earth by two of the three coordinates of a spherical coordinate system which is aligned with the spin axis of Earth.