Species extinction occurs when a particular type of organism, such as a plant or animal, no longer exists anywhere on Earth. This can happen due to various factors, including habitat loss, climate change, pollution, and overhunting. When a species goes extinct, it can disrupt ecosystems and affect other species that rely on it for food or habitat. The extinction of species is a natural process, but human activities have accelerated this rate significantly. For example, the Passenger Pigeon and the Woolly Mammoth are well-known species that have become extinct largely due to human impact. Conservation efforts aim to protect endangered species and prevent further extinctions.