# Coordinate The `Coordinate` class is the most important class of phpgeo and provides the base for all features. It's a representation of a geographic location and consists of three parts: - Geographic Latitude - Geographic Longitude - Ellipsoid Geographic latitude and longitude values are float numbers between -90.0 and 90.0 (degrees latitude) and -180.0 and 180.0 (degrees longitude). The Ellipsoid is a representation of an approximated shape of the earth and is abstracted in its own [`Ellipsoid`](Ellipsoid) Link class.