Tropics
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The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at 23°26′10.0″ (or 23.43612°) N and the Tropic of Capricorn in
the Southern Hemisphere at 23°26′10.0″ (or 23.43612°) S. The tropics are also referred to as the tropical zone and the torrid zone.
Aerial view of Bora Bora in French Polynesia
Tropical sunset over the sea in Kota Kinabalu in Malaysia
Coconut palms in the warm, tropical climate of Pajuçara in northern Brazil
Dragon fruit, a tropical fruit from several different cacti originally from the Americas
Season
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A season is a division of the year based on changes in weather, ecology, and the number of daylight hours in a given region. On Earth, seasons are the result of the axial parallelism of Earth's tilted orbit around the Sun. In temperate and polar regions, the seasons are marked by changes in the intensity of sunlight that reaches the Earth's surface, variations of which may cause animals to undergo hibernation or to migrate, and plants to be dormant. Various cultures define the number and nature of seasons based on regional variations, and as such there are a number of both modern and historical cultures whose number of seasons varies.
Axial parallelism is a characteristic of the Earth (and most other orbiting bodies in space) in which the direction of the axis remains parallel to itself throughout its orbit.
Illumination of Earth at each change of astronomical season
Two images showing the amount of reflected sunlight at southern and northern summer solstices respectively (watts / m2).
Four Seasons by Alphonse Mucha (1897)