L is for longitude and latitude. I know it is two words but work with me here. Longitude and latitude have been used for hundreds of years to navigate around earth. Here is a definition from http://whatis.techtarget.com: Latitude and longitude are angles that uniquely define points on a sphere. Together, the angles comprise a coordinate scheme that can locate or identify geographic positions on the surfaces of planets such as the earth.
Here is a good article about the history https://www.broward.org/library/bienes/lii14010.htm.
It explains that as new inventions such as the clock and the satellite that longitude and latitude became easier to track and maps became more accurate. For example googlemaps has a help page where you can find the latitude and longitude coordinates for a specific place.
What I find the most interesting is that no matter what the technology is longitude and latitude are the basis for it and that is why I chose to write about it.