What is the difference between critically endangered endangered vulnerable and threatened species?

These are the different categories defined by the IUCN that are given below in detail.

Explanation:

The right question goes like this, "what is the difference between critically endangered, endangered, vulnerable, and threatened species?"

The answer to this question is,

International Union for Conservation of Nature (IUCN) classifies species into nine groups through unique criteria such a rate of decline, size and degree of population, geographical distribution, and so forth. The following are some of those categories.

Critically Endangered: The species in this category are likely to go extinct soon unless some drastic measures are taken to ensure its survival. e. g., Bluefin tuna. Endangered: The species in this category are at high risk of extinction in the wild. e. g., Green sea turtle. Vulnerable: The species in this category face a high risk of unnatural extinction in the near future. e. g., Komodo dragons.

According to IUCN "Threatened" embraces the divisions of Critically Endangered, Endangered, and Vulnerable.