What function does latitude and longitude have other than plotting Geographic Coordinates?

These coordinates are what the Global Position System or GPS uses to provide an accurate locational relay. Longitude and latitude lines measure the distance from the Earth's Equator or central axis - running east to west - and the Prime Meridian in Greenwich, England - running north to south.

I hope this is what you are looking for... If not I am sorry for not providing the correct/accurate answer. (^-^)