People have been creating maps for more than 4,000 years to organize information about the world. Mapmakers use lines, symbols and colors to designate various things on the map. Stars or dots inside a circle represent different kinds of cities.
The capital city of a country is designated by a circled star. Capital cities of states or provinces are usually marked by a dot within a circle. Capital cities are primarily found on political maps and may not appear on a contour, or physical, map. Political maps show the name and boundary markers of a country and its capital city and often will include major landforms.
Another symbol found on political maps is a dark black dot. These dots often represent a major city other than the capital. In most cases, the larger and darker the black dot is, the higher the population compared with other cities marked on that map.
Most maps contain a map key or legend that explains the symbols the mapmaker used. Sometimes the legend is very small, but it can usually be found in one of the corners on the face of the map. If the map is bound into a book or booklet with other maps, a single legend is sometimes found at the beginning of the book. Map keys often contain information about the symbols, a direction marker, a scale bar or measuring line, and the year the map was published.