For example, one inch on a map could depict a distance of one hundred miles. Keys are used to explain what the different symbols in a map mean. The symbol for railroad tracks, hospitals or state capitals may all be shown in the key.
Grids are lines on some maps that form squares like a chess board.
The squares divide the map up into smaller sections. Things are easier to find that way. Longitude and Latitude Longitude lines run from the North Pole to the South pole. They are called meridians. Latitude lines run west to east.