What Are Maps?

Maps are two-dimensional (flat) representations of three-dimensional spaces. People have been making maps for over 4,000 years, and they've come a long way. We used to rely on explorers to visit faraway places before a map could be made. We still have explorers that travel the Earth (and beyond) to discover and map new places, but now we can also make and update maps with information sent from satellites in space.

All maps have five basic elements to help you understand them (numbers match image below):

1. A title, to tell you the "who," "where," and "when" about the map
2. Orientation (north, south, east, or west)
3. Scale to determine distance
4. A legend that explains the shapes, colors, and symbols used
5. A grid or coordinates that help show where the map fits into a larger global area

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Mapmaking

The science and art of mapmaking is called cartography. From cave paintings and ancient European maps to new maps of the 21st century, people have created and used maps to help define, explain, and navigate their way across the planet and beyond.

Where maps were once hand-drawn on paper, most modern cartographers now use a variety of computer graphics programs to generate new maps. For example, we have technologies like Global Positioning System (GPS) for navigation and Geographic Information Systems (GIS) to analyze and display information.

Global Positioning System (GPS)

GPS is a global positioning system that uses satellites to pinpoint your location anywhere on the planet.

How does it do that? Your GPS-enabled device—such as a cell phone, car navigation system, or handheld GPS unit—determines your location by measuring the time delay between when a satellite sends a signal and when your unit receives it.

With more than 24 GPS satellites in orbit around the Earth, GPS has become very popular for navigation on land, sea, and air, as well as an important tool for mapmaking and land surveying.

Geographic Information Systems (GIS) GIS is a computer-based technology that enables people to quickly combine different types of information (such as population, precipitation, and transportation) on a single map. GIS represents real-world objects (roads, a house, rainfall amount, land elevation) with digital information, and GIS technology can be used for all kinds of things—scientific investigations, managing natural resources, cartography, and route planning, to mention just a few.

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Types of Maps and Their Uses

Maps can show us all kinds of useful information:

Natural features, such as mountains, lakes, and rivers

Political areas, such as city, state, and country borders

Scientific information, such as rainfall amounts or population numbers

Navigation features, such as roads, subway stops, and ocean depths

There are two main types of maps:

Reference maps help us navigate. They show things like roads, city capitals, bus stops, stars in the Milky Way, or rooms in a museum.

Thematic maps help us interpret specific kinds of information. For example, maps may show the population of city, the weather in another country, or the types of animals living in a national park.

Maps are used by everyone from geographers to travelers to hikers to airline pilots. No matter what content is shown by maps, they can transport us places far away or help us explore the areas near our homes.