Latitude
The latitude of a point on Earth is the angle between the equatorial plane 
and the line passing through the point at right angle to the surface of the 
ellipsoid (see figure above). 
The Earth is divided into 90 degrees of latitude going both northwards and 
southwards from the equator (0) to each pole (90 N and 90 S). 
Normally northern positions are considered to be postive (+) and southern 
positions to be negative (-).

Longitude
The longitude of a point on Earth is the angle along the equator between 
the prime meridian passing through Greenwich and the meridian passing through 
the point (see figure above). 
The Earth is divided into 180 degrees of longitude going both eastwards and 
westwards from the prime meridian (0) until meeting approximately at the 
international date line (180 E = 180 W).
Normally eastern positions are considered to be postive (+) and western 
positions to be negative (-).

Divisions
One degree (  ) is normally divided into 60 minutes (  ) or decimals.
One minute (  ) is normally divided into 60 seconds (  ) or decimals.
One second (  ) is normally divided into decimals (when divided).