What is a geographic coordinate system primarily used for?

A geographic coordinate system is fundamentally utilized for defining precise locations on Earth through the use of latitude and longitude. This system offers a universal framework that allows geographers, urban planners, and other GIS professionals to pinpoint the coordinates of any place on the globe. By providing the angular measurements of how far north or south (latitude) and east or west (longitude) a location is from the equator and the prime meridian, respectively, the geographic coordinate system enables easy communication and understanding of specific places in a spatial context.

In contrast, the other choices relate to different aspects of spatial analysis or representation. Measuring land use refers to assessing how land is utilized, which involves qualitative and quantitative data, rather than strictly geographical coordinates. Calculating population density involves spatial analysis of demographic data and is typically undertaken in projection systems that distort geographic coordinates to create meaningful visualizations. Lastly, representing data in a two-dimensional form pertains more generally to how GIS data can be displayed or visualized, rather than the specific function of geographic coordinate systems. Therefore, the primary and most direct use of a geographic coordinate system is to define locations on Earth using latitude and longitude.