What exemplifies extinction?

Extinction is the complete disappearance of a species from life. No more of that species is alive on the planet. It happens all the time; the normal rate of extinctions is called the background...

Extinction is when a animal doesn't exist any more, because all of its species has died out completely. It Can Also Be When Only A Few Animals Live But Most Are Dead Just Like A Mammoth is dead.

A species is extinct when all members of that species are dead.

Mass extinction- More than 50% of the population went extinct in a short period of time. Background extinction- An average rate of extinction for a given time period.

Both involve at least a few species dying out because of failure to adapt to the changing environment.