Extinction means that certain animals or plants that were there for a long time before no longer exist on earth. When the last animal or plant of a species has died, the whole species of animal or plant has become extinct. Such creatures will then never exist on earth again. An example is the dinosaurs, whose extinction dates back about 65 million years.
Sometimes a single animal species becomes extinct, such as the aurochs. Sometimes only a subspecies becomes extinct, such as the northern white rhinoceros, of which there were only two females left in 2022, but no bull. Sometimes, however, an entire genus, a family or an even larger group becomes extinct.
Extinction can also take place only in a certain area. In Switzerland, the last brown bear was shot in 1914. Since then, it has been considered extinct in Switzerland. Or rather, it was exterminated. Today, there are brown bears again in Switzerland that have migrated from Italy.