The classification is in this order: Kingdom, Phylum, Class, Order, Family, Genus Species.
The kingdom is the largest group, it contains the largest number of organisms who are the least related.
The species is the smallest group, it contains the least number of organisms who are closely related.
As you go down, from "Kingdom", species become more closely related.
So species in the same family are MORE closely related than species in the same class.
An endangered species is a type of species in which this type of organism has decreasing numbers and are dangerously close to going extinct. Invasive species are species in which an organism invades an environment where it is not native to, and take over the ecosystem. Local species are species in which the organism is native to that environment and plays a key role in that ecosystem. A keystone species is a species in which the organism is a key part of that ecosystem to thrive; without it, the ecosystem would collapse