The document defines key terms related to astronomy, cartography, and geography. It explains that an artificial satellite is an object made by humans that orbits Earth, and defines terms like galaxy, Milky Way, orbit, planet, star, and solar system from an astronomical perspective. It also defines cartography terms including map, map projections, scale, coordinates, meridian, Greenwich Meridian, longitude, parallel, equator, latitude, and hemisphere for describing locations on Earth.