In this case the mapping data is sold by degrees of latitude and longitude. As a reference, if you are interested in the Big Bear, San Bernardino National Forest area, it is 3 latitude x 3 longitude. The chief drawbacks of this program are its price and difficulty of acquisition. A map is a two-dimensional, graphic representation of the earth's surface drawn to scale. Maps come in many shapes and sizes and have traditionally been printed on paper.
Most people are familiar with a highway map or a street map.
This map shows the relationship of city streets or highways to each other, but does not show elevation or other geologic information. Elevation is represented by contour lines, and symbols and colors represent man-made or geographic features. The scale of a map is the amount of distance represented by a measurement on the map and how it relates to distance on the ground. As the scale of a map increases, the amount of detail shown is less. Precisely walking a contour line would mean that you never change elevation.