Latitude and Longitude
nLatitude represents an angular
distance along a meridian north or south from the equator.
nLongitude is an angular distance of
a point on the earth's surface east or west of an arbitrarily defined meridian, usually the
Greenwich meridian (Greenwich, England).
nA line of longitude running
vertically from the north pole to the south pole, but unlike lines of longitude, meridians terminate at the
poles.
nThe Prime Meridian, currently
called the Greenwich Meridian, runs through Greenwich, England, was agreed in 1884 as being the
central meridian from which all other meridians would be referenced to in order to
calculate longitude.