Map

A map is an image of the Earth or part of the Earth. A map is different from an aerial photograph because it includes interpretation. Many maps are called "charts" such as star charts and nautical charts. Some maps are of distant worlds. Before the late 20th century almost all maps were on paper. Today, many maps are digital, and can be seen on smartphones and computers. However, physical items such as paper maps, charts, or drawings are still used. The word "map" can also be used to talk about or show relationships between ideas, people, events, data, and many other subjects. This is why web developers call a list of web pages on a web site a site map.

Many maps today are made using GIS computer systems. These are database systems that are organized by location instead of named records. People who make maps are cartographers. If a map is on a piece of paper or a computer screen, it has to be projected. This is because the Earth is round and paper and screens are flat. There are a lot of ways that use mathematics to make map projections. The only kind of map of the Earth that is not projected is one drawn on a sphere. This is called a globe.