What is a hemisphere?

A hemisphere is half of a sphere, or a half of the Earth when divided into northern and southern halves (Northern Hemisphere and Southern Hemisphere) or eastern and western halves (Eastern Hemisphere and Western Hemisphere). It can also refer to any half of a spherical or roughly spherical object.

A hemisphere is half of a sphere. It is a three-dimensional shape with two circular surfaces and a curved edge. The two circular surfaces meet along the edge, which is the circumference of a circle. Hemispheres are often used to represent half of the Earth, since the Earth is approximately a sphere.