1.  Grid Systems -how to locate places on a map

2. Alphanumeric Grid  This type of grid system uses letters and numbers to identify squares in a grid pattern.  This type of grid is often used on road maps. Grid squares are identified by letters on one side of the map, and a number on the other side.

3. Map Grid (Military Grid)  Used on topographic maps, shown as blue lines.  Each vertical line is called an easting and runs from the top to the bottom of the map.  Each horizontal line is called a northing and runs from left to right.

4. Latitude and Longitude  This type divides the earth into a series of grid squares.  Latitude runs horizontal around the earth, and run parallel to the equator  Longitude runs vertical (up and down) around the Earth.