Biotic factor

"All the living organisms that inhabit an environment are called biotic factors" (Biology: The Study of Life, Glencoe)

As opposed to abiotic factors (non-living components of an organism's environment, such as temperature, light, moisture, air currents, etc.), biotic factors are the living components of an organisms environment, such as predators and prey.

For example, if one were to examine a desert ecosystem for biotic and abiotic factors, one would observe things like the extreme temperatures of the day and night, the fast winds, the heavy amount of sunlight, and scarcity of water as abiotic, or NON-living factors in the environment. One would observe that for a quail living in the desert, living elements like the quail's prey (insects, seeds, etc.) and predators (coyotes, sparrow hawk, gold eagles, etc.) make up the biotic factors of the quail's environment.