Basic Map Vocabulary A map is a graphic representation of a place. An atlas is a book of maps or charts. A compass rose is a symbol on a map that shows direction. A map key or legend is a table on a map that lists and explains the symbols on map. Map Key The scale on a map gives the distance between two points on a map. Map Scale The equator is an imaginary line around the Earth. The equator divides our planet into the northern and southern hemispheres. It measures 0 latitude. Equator The prime meridian is an imaginary line around the Earth. It represents 0 longitude. The prime meridian divides our planet into the western and eastern hemispheres. Prime Meridian The term hemisphere means half of a sphere or ball shape. Our planet is divided into hemispheres. The northern hemisphere is the half of the Earth that is north of the equator. Northern Hemisphere The southern hemisphere is the half of the Earth that is south of the equator. Southern Hemisphere The eastern hemisphere is the half of the Earth east of the prime meridian. The eastern hemisphere includes the continents of Asia, Africa, Europe, and Australia. Eastern Hemisphere The western hemisphere is the half of the Earth west of the prime meridian. The western hemisphere includes the continents of north and south America. Western Hemisphere Northern Hemisphere Western Hemisphere North America North America is located in the northern and western hemispheres. To find an exact location on a map, a grid system of lines is used. The imaginary lines used to create the grid are called lines of latitude and longitude. Exact location of a place is measured in degrees latitude and longitude. Latitude lines run parallel to the equator. The equator is at 0 latitude. Latitude Lines Longitude lines run parallel to the prime meridian. The prime meridian is at 0 longitude. Longitude Lines