All organisms require specific abiotic factors in order to survive. For example, most animals can't survive if the temperature is above 45°C. But some bacteria are found living in hot springs with temperatures greater than 100°C. These necessary abiotic and biotic factors determine a species' habitat. The location of these habitats will determine a species' range. An organism living in its habitat has a role to play — it has certain biotic and abiotic needs in order to survive. This is called the organism's niche.

Many organisms can share habitats because they have different niches. For example, a forest will have a canopy of tall coniferous trees that require large amounts of sunlight and ground cover plants where little light gets through. Animals with a very small niche, such as the panda bear that eats only bamboo, may have a higher risk of becoming endangered. Since the animal's niche (role and resource requirements) is smaller, it would be greatly affected by one food source disappearing. It would have a limited range due to having a less diverse diet.