Longitudes and Latitude

Longitudes
Longitudes are imaginary vertical lines that run in a north-south direction from the North Pole to the South Pole. It is also the angular distance from a point's meridian from the Greenwich Meridian, also known as the Prime Meridian. It is usually expressed in degrees and minutes. Lines of longitude are often referred to as meridians. The Greenwich Meridian is the zero degree longitude.

The measurement of longitude is important to both cartography and to provide safe ocean navigation. Mariners and explorers for most of history struggled to determine precise longitude. Longitude is given as an angular ranging from zero degrees at the Prime Meridian to  +180° eastward and −180° westward. The Greek letter λ( lambda), is used to denote the location of a place on Earth east or west of the Greenwich Meridian.

Longitude at a point may be determined by calculating the time difference between that and its location and Coordinated Universal Time( UTC). Since there are 24 hours in a day and three hundred and sixty degrees in a circle, the sun moves across the sky at a rate of fifteen degrees per hour.

Latitude
Latitudes are imaginary horizontal lines that run in an east-west direction round the Earth. The latitude is an angle and is usually measured in degrees. The Equator, the longest line of latitude which divides the Earth into two equal halves, has a latitude of zero degrees. The North Pole have a degree of ninety degree north and the South Pole have a degree of ninety degree south. The Tropic of Cancer have a degree of twenty three point five degree north while the Tropic of Capricorn have a degree of twenty three point five degree south. The Arctic Circle have a degree of sixty six point five north and the Antarctic Circle have a degree of sixty six point five south.

A region's latitude has a great effect on its climate and weather. Latitude more loosely determines prevailing winds, and other physical characteristics of geographic locations. Auroral activity is common at high geomagnetic latitudes.  
Click here to watch a video on latitude and longitude: http://www.youtube.com/watch?v=swKBi6hHHMA