An "extinct species" is a species of organism that can no longer be found in the wild or in captivity. It is already dead and can no longer be found in any part of the world.

The plant or animal species existing in such small numbers it is in danger of becoming extinct, especially such a species placed in jeopardy because of human activity. The specie is on the verge of extinction and have few numbers. If proper measures are not taken then it can also become extinct if proper care and measures are taken then their population can be increased.