Maps
Maps are images that can provide very useful information about a specific geographic area. The images are often overlaid with text that helps the reader understand and interpret the information provided by the images on the map.
A good map will have a "key" or a "legend" which explains what the map shows and decodes any symbols used on the map.
Another extremely important feature of a map is a scale. This provides you with a sense of how large an area the map covers. The scale is usually set so that one inch equals a much larger measurement.
Side note: the science of making maps is called "cartography".
Click here to see a few different maps of the United States.