Simplify the following text for a Grade 12 native English-speaking person.
Original: Endemism is the ecological state of being unique to a defined geographic location , such as an island , nation or other defined zone , or habitat type , and found only there ; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere .
Simplified: Endemism is an ecological word meaning that a plant or animal is only found in a particular location , such as a specific island , habitat type , nation or other defined zone .