Imagine the world is a big playground with lots of different areas to explore. Each area has its own unique toys and games to play with. Now imagine that instead of a playground, it's the whole world and instead of toys and games, it's different kinds of animals and plants that live there. Each area has its own group of animals and plants that are unique to that area.
These areas are called biogeographical realms. A realm is a big area of land or water where animals and plants live that are similar to each other. There are seven different biogeographical realms on Earth, and they are divided based on things like geography, climate, and evolution.
For example, the Neotropical realm is in Central and South America, and it has a lot of different kinds of tropical animals like monkeys, toucans, and jaguars. The Nearctic realm is in North America, and it has animals like bears, coyotes, and deer.
Scientists use biogeographical realms to help them understand how animals and plants have evolved over time and how they are connected to each other. By studying the animals and plants in each realm, they can learn more about how they interact with each other and the environment around them.