A species enters an environment where has not lived before is called a what?

A species that enters an environment where it has not lived before is called an "invasive species" if it establishes a population and disrupts the local ecosystem. Such species can outcompete native species for resources, alter habitats, and introduce new diseases. In contrast, a species that colonizes a new area without causing harm might simply be referred to as a "non-native" or "exotic" species.