Latitude and Longitude

Latitude  (North-South): the lines parallel to the Equator (horizontal on the map),  running east to west. Zero degrees is at the Equator, then the lines run to 90°  north (+90°) at the North Pole, and 90° south (-90°) at the South Pole. (The  North Hemisphere is positive, the South is negative.)

Longitude  (East-West): the vertical lines (meridians) running from the North Pole to the  South Pole. These divide the sphere of the Earth into 360 slices. Zero degrees  starts at the Prime Meridian, which runs through the observatory at Greenwich, England.  The east and west meridians meet at 180° on the opposite side of the Earth;  this line is also the International Date Line. It takes 24 hours for any point  on the Earth to traverse the full 360°.

24 hours of time =  360° of longitude
1 hour of time = 15°
4 minutes of time =  1°
1 minute of time = 15′
1 second of time = 15″

Both latitude & longitude are divided into degrees (°), then minutes  (′) and seconds (″). Degrees can also be  expressed as decimal co-ordinates.

for more information check out these links from NASA.