Latitude lines are the horizontal lines on a map. Latitude lines are parallel to each other they have an equal distance from each other. In the north hemisphere, the degrees of latitude range from 0° to 90° N, and in the south hemisphere, the degrees of latitude range from 0° to 90° S. The 0° line refers to the equator, which is the line which divides our planet into the northern and southern hemispheres. 90° N is the North Pole and 90° S is the South Pole.

     Longitude (meridians) are the vertical lines on a map. They all converge at the two poles (the North Pole and the South Pole), and 0° longitude is located at Greenwich, England (0°). In the east hemisphere, the longitude ranges from 0° to 180°E, and in the west hemisphere, the longitude ranges from 0° to 180°W. Actually, the 180°E and 180°W are the same lines (so most of the time we just call it longitude 180°). The International Date Line in the Pacific Ocean is defined based on longitude line 180°, but there is a zigzag border on the International Date Line near the Bering Sea because that is to keep Russia’s north & west territory of the Bering Sea and the United States’s east and south territory of the Bering Sea (which is Alaska), on opposite sides of the line in agreement with the date in the rest of those countries.

     In order to locate spots on the earth’s surface, we combine the use of latitude and longitude. Because of accuracy, we not only use degrees (°) but also minutes (‘), and even seconds (”). E,W,N,S have to be used to indicate which hemisphere we are referring to. 

Look at the map below:

From this map, if you know where New York City is (if not, try to Google for a map that can tell you where New York City is), you can see it is located at roughly 40° N, 74° W.

I have mentioned about accuracy. Yes, New York City is very big, so when you are referring to the location of a building, for example, the Empire State Building, you can’t just use degrees, but also minutes and seconds. Even though minutes and seconds are not shown in the map above, accurate maps will have them. Empire State Building is located at 40°44′54.36″N73°59′08.36″W.

This data is from the satellite, so it is so accurate that it even has two extra digits after decimal points of second(“) !!