A map is a symbolic depiction emphasizing relationships between elements of some space, such as objects, regions, or themes.
Many maps are static, fixed to paper or some other durable medium, while others are dynamic or interactive. Although most commonly used to depict geography, maps may represent any space, real or fictional, without regard to context or scale, such as in brain mapping, DNA mapping, or computer network topology mapping. The space being mapped may be two dimensional, such as the surface of the Earth, three dimensional, such as the interior of the Earth, or even more abstract spaces of any dimension, such as arise in modeling phenomena having many independent variables.
Although the earliest maps known are of the heavens, geographic maps of territory have a very long tradition and exist from ancient times. The word "map" comes from the medieval Latin: Mappa mundi, wherein mappa meant 'napkin' or 'cloth' and mundi 'the world'. Thus, "map" became a shortened term referring to a two-dimensional representation of the surface of the world.
Maps have been one of the most important human inventions for millennia, allowing humans to explain and navigate their way through the world. The earliest surviving maps include cave paintings and etchings on tusk and stone, followed by extensive maps produced by ancient Babylon, Greece and Rome, China, and India. In their most simple form maps are two dimensional constructs, however since the age of Classical Greece maps have also been projected onto a three-dimensional sphere known as a globe. The Mercator Projection, developed by Flemish geographer Gerardus Mercator, was widely used as the standard two-dimensional projection of the earth for world maps until the late 20th century, when more accurate projections were formulated. Mercator was also the first to use and popularise the concept of the atlas as a collection of maps.
Cartography or map-making is the study and practice of crafting representations of the Earth upon a flat surface[1] (see History of cartography), and one who makes maps is called a cartographer.
Road maps are perhaps the most widely used maps today, and form a subset of navigational maps, which also include aeronautical and nautical charts, railroad network maps, and hiking and bicycling maps. In terms of quantity, the largest number of drawn map sheets is probably made up by local surveys, carried out by municipalities, utilities, tax assessors, emergency services providers, and other local agencies. Many national surveying projects have been carried out by the military, such as the British Ordnance Survey: a civilian government agency, internationally renowned for its comprehensively detailed work.