Carrying capacity is the theoretical equilibrium population size at which a particular population in a particular environment will stabilize when its supply of resources remains constant. It can also be considered to be the maximum sustainable population size; the maximum size that can be supported indefinitely into the future without degrading the environment for future generations.
Example of Carrying Capacity:
In any environment, it is important to understand the carrying capacity of a certain species in the ecosystem. When there were only very few wolves in the Yellowstone national park, the elk population are not controlled and exceeds the carrying capacity of the park. As a result, they over consumed the resources of the park such as the willow trees, resulting in a far more serious ecological damages.