Refers to one hemisphere of the Earth's surface divided along either the equator or the Prime Meridian.
Related terms
Equator: An imaginary circle around the middle of the Earth that divides it into Northern and Southern Hemispheres.
Prime Meridian: The imaginary line that runs from North Pole to South Pole through Greenwich, England, dividing the Earth into Eastern and Western Hemispheres.
Hemisphere: One half of a sphere or globe. In geography, it refers to one half of the Earth divided by either latitude (North/South) or longitude (East/West).