The equator is an imaginary line located at 0 degrees latitude, stretching around the middle of the Earth. It divides the planet into the Northern and Southern hemispheres. Daytime at the equator always lasts 12 hours, with night also lasting 12 hours.
Countries through which the equator passes include Indonesia, Kenya, Ecuador and Brazil. The equator stretches around the planet for 24,901.55 miles, or 40,075.16 kilometers.
The Prime Meridian, at 0 degrees longitude, is the imaginary line that divides Earth into its Eastern and and Western hemispheres. Some people recognize slightly different boundaries for the hemispheres to keep Africa and Europe entirely in the Eastern Hemisphere.