Any two-dimensional graphic representation of the physical features (natural or man-made) of all or a portion of the surface of the earth or another celestial body, the heavens, or an imaginary geographic area, normally done to scale on a flat medium using a specified projection, with an indication of orientation, but increasingly in digital form. Early maps were drawn on parchment stored in rolls. In modern libraries, maps are usually stored flat or folded in a specially designed map case with wide, shallow drawers. Maps are also included as inserts or pocket parts in books and periodicals. As illustrations, they may be printed as plates with the text or on the endpapers. An atlas is a book consisting almost entirely of maps, with the content usually indexed in a gazetteer at the end. The largest mapping agency in the United States is the U.S. Geological Survey. Click here to connect to a historical map collection available online, courtesy of the American Memory project at the Library of Congress. Other examples can be seen by browsing the Perry-Castañeda Library Map Collection (University of Texas at Austin) and the online exhibitions provided by the Osher Map Library, University of Southern Maine. For interactive maps, try the National Geographic Society. Compare with globe. See also: cartography, cartouche, legend, map continuation, map series, and projection.
Maps are categorized by the type of content and method of presentation. See also: ancillary map, artistic map, base map, bathymetric map, cadastral map, cartogram, chart, choropleth map, city map, cloth map, compiled map, computer-generated map, contour map, decorated map, dynamic map, facsimile map, geologic map, gravity map, historical map, hydrologic map, index map, inset map, interactive map, isoline map, landscape map, location map, main map, manuscript map, mappa mundi, mental map, multimedia map, old map, outline map, photomap, pictorial map, planimetric map, political map, rare map, reconnaissance map, relief map, road map, schematic map, scroll map, sketch map, slope map, strip map, tectonic map, thematic map, topographic map, trail map, translucent map, wall map, war map, and world map.