A map usually has a legend, or key, that gives the scale of the map and explains what the various symbols represent. Green is often used for forests, tan for deserts, and blue for water. For example, black dots represent cities, circled stars represent capital cities, and different sorts of lines represent boundaries, roads, highways, and rivers. Symbols Cartographers use symbols to represent geographic features. A person may begin by looking at the map of an entire city that only shows major roads and then zoom in so that every street in a neighborhood is visible. Many computerized maps allow the viewer to zoom in and out, changing the scale of the map. A map of a larger area, such as a continent or the world, is called a small-scale map because objects on the map are relatively small. A map that shows an area in great detail, such as a street map of a neighborhood, is called a large-scale map because objects on the map are relatively large. The size of the area covered helps determine the scale of a map. One inch on the map represents 1,000,000 inches on Earth, or a little less than 16 miles. So, 1 centimeter on the map represents 1,000,000 centimeters on Earth, or 10 kilometers. This means that any given unit of measure on the map is equal to one million of that unit on Earth. For example, a verbal scale might say, “one centimeter represents one kilometer” or “one inch represents eight miles.” The representative fraction does not have specific units. The verbal scale is a sentence that relates distance on the map to distance on Earth. Also called a bar scale, it is simply a horizontal line marked off in miles, kilometers, or some other unit measuring distance. The most common type of graphic scale looks like a ruler. This relationship can be expressed by a graphic scale, a verbal scale, or a representative fraction. A map’s scale indicates the relationship between the distances on the map and the actual distances on Earth. Scale All maps are scale models of reality. Some common features of maps include scale, symbols, and grids. City planners decide where to put hospitals and parks with the help of maps that show land features and how the land is currently being used. Meteorologists-scientists who study weather-use weather maps to prepare forecasts. Vacationers use road maps to plot routes for their trips. Mapmakers, called cartographers, create maps for many different purposes. They can show exact locations of houses and streets in a city neighborhood. Maps can show distributions of things over Earth, such as settlement patterns. They teach about the world by showing sizes and shapes of countries, locations of features, and distances between places. Maps present information about the world in a simple, visual way. A map is a symbolic representation of selected characteristics of a place, usually drawn on a flat surface.

Citizens of earth world map