An atlas in simple terms is a book of maps. It has the possibility of being less unwieldy in a car, offering more detail, covering more area or focusing on a particular theme.
World Atlases are excellent educational and reference tools for all ages, and make wonderful unique gifts. The same can be said for Historical Atlases, subjects range from general world history to specific areas or subjects - like railroads. Road atlases show more detail, but are easier to manage in a car and can sometimes be larger print that a folded map.
What could be better than a map...a book of maps!