What is one of the main reasons we divide the world into eastern and the western hemisphere rather than it did the northe what is one of the main reasons we divide the world into eastern and the western hemisphere rather than into the northern hemisphere and the Southern Hemisphere

The Equator, or line of 0 degrees latitude, divides the Earth into the Northern and Southern hemispheres ... There are differences in the climates of the Northern and Southern hemispheres because of the Earth's seasonal tilt toward and away from the sun.

The Eastern Hemisphere refers to the area of the Earth east of the prime meridian and west of the International Date Line. This includes much of Europe, Africa, Asia, Australia, and the islands of Oceania. A map centered on the Eastern Hemisphere will have the Indian Ocean basin at the center.