They consist of all geographic regions on Earth where the Sun makes direct contact with a point immediately overhead (a subsolar point) at least once every solar year. The tropics' greatest latitudes thus have the same positive and negative value. They also estimate the "angle" of the Earth's axial tilt because the planet is not a perfect sphere. The moon's effect is the main reason why the "angle" is not totally set, but the bounds of the tropics are a geographic convention because they are an averaged form and the variance is relatively tiny.

The equator and portions of North America, South America, Africa, Asia, and Australia are all considered to be in the tropics.

A third of the world's population resides in the tropics, which cover 36% of the planet's landmass and 40% of its surface.

They are often hotter and drier and receive more direct sunlight than the rest of the planet.

The various climates of the Tropics are a result of a variety of factors. The mean annual temperature exceeds 20°C practically everywhere in the Tropics, with the exception of high elevations, and exceeds 25°C in several areas of the tropical zone, making it a warm region.

The tropical region includes both some of the wettest and driest desert regions on the planet.

As a result of population pressures driving settlement in flood- or drought-prone areas and a lack of resources in less developed nations, it also comprises some of the populations that are most vulnerable to natural disasters.

The tropical region is distinguished by constant warmth and minuscule daily temperature variations.

 Tropical regions have minimal temperature changes, but they also have a huge variety of rainfall patterns.

In the tropics, the types of plants and animals that can be found there directly depend on how much rain falls there. For example, the baobab tree flourishes in the dry tropical regions of Africa. Water is kept inside the baobab's enormous trunk. The Indian Ocean's rainy island of Sri Lanka represents the other extreme. It rains enough in Sri Lanka to support 250 different kinds of frog.

Because the apparent location of the Sun shifts between the two tropics in a year, the name "tropics" is derived from the Greek tropos, which means "turn."

The term "Tropical" refers exclusively to locations close to the equator. The term is also occasionally used to refer generally to a tropical climate, which is one that is warm to hot and humid all year round.