Other maps contain natural geographic landmarks such as mountain ranges, rivers, lakes, shorelines, and islands. Maps of this type can be topographical, or they may incorporate satellite photography. These maps contain data from a wide variety of sources ranging from government agencies such as the U.S. Geological Survey and other international agencies as well as from the private sector. Some charts may also be included that depict oceanographic data such as depth, currents, and other useful navigational data. These may be used for expeditions, recreational activities, or for programming GPS receivers. Some land charts include data on natural resources that may be referenced for a wide variety of business and industry needs. Special maps for aeronautical, recreational vehicle, and other specialized needs require researching alternative sources such as local and national governmental agencies, business sources, and proprietary software companies.
World atlases usually include statistical and government information such as capitals, flags, populations, climates, economies, and crops. This data is especially useful for personal, educational, and business studies when presented in an easily understood, graphical format. Research to plot trends in the areas of population growth, climate, and economics can be accomplished by studying and comparing different year editions. These comprehensive reference guides have traditionally been available in print format, but user-friendly information about the oceans, continents and countries of planet Earth is also available online.
A detailed map of the world, with countries identified by two-letter country codes, can be found on this world map page.