Native species - a species that is native (or indigenous) to a given region or ecosystem if its presence in that region is the result of only natural processes, with no human intervention.

Endangered species - a species at risk of extinction because of human activity, changes in climate, changes in predator-prey ratios, especially when officially designated as such by a governmental agency.

Exotic species - a species introduced either accidentally or deliberately by human actions into places beyond its natural geographical range.

Parasite - an organism that lives on or in an organism of another species, known as the host, from the body of which it obtains nutriment.