What is the natural areas?

But our planet is spherical. Therefore, sunlight falling on its surface at different angles and different heats. At the equator, the sun's rays are directed to the ground almost at a right angle. And twice a year the sun at midday stops at the zenith, directly overhead. Quite differently heated pole. Where the sun hangs over the horizon, and then several months in a row does not show at all. And this means the amount of heat which is received by a small pole. Equator same temperate latitudes receive much more heat. Therefore, in both hemispheres of the Earth there are several thermal zones: equatorial, two tropical and two temperate and two cold. And because the uneven distribution of heat seen on the surrounding nature, then stand still and geographic zones. Their boundaries coincide with the boundaries of thermal belts. The width of each geographical zone in some places reaches more than 4 thousand kilometers. Therefore, in each of these natural conditions are also different. The closer to the equator, any portion of the geographic zone, the more heat it gets and the more unlike the previous one. These differences are noticeable on flora and fauna, climate, soils. Therefore, within the geographical zones are allocated more or less homogeneous in terms of area. They are called natural. They stretch bands along the parallels of the globe, as it were, starting at one end and ending at the other.