The traditional coordinate system based on latitude and longitude. Coordinates are measured using degrees, minutes, and seconds, measured angularly from the Earth's center from the Equator and the Prime Meridian. Latitude is measured from the Equator, while longitude is measured from the Prime Meridian.
Imagine that lines of latitude and lines of longitude form a grid over the Earth's surface. A point (coordinate) is formed by the intersection of a latitude line and a longitude line. In this way, any location on the earth can be determined.