Biotic factors are living. Abiotic factors are non-living factors like temperature, oxygen levels, wind, water, soil composition, and humidity. In any given ecosystem, the organisms that are surviving there depend on being able to obtain and use energy. For producers, this generally means that they need access to abiotic factors like sunlight, water, and carbon dioxide. Those producers form the base of food chains, food webs, and trophic level pyramids. Primary consumers eat the producers. Secondary consumers depend on the presence of previous consumers and so on up the food chain. If a population of consumers grows too large, then there won't be enough organisms a step down in the food chain to support such a large population.
Animals are food for each other, and plants are food for animals. Plants and animals are living creatures. They are biotic; therefore, food availability is a biotic limiting factor. A wolf population can't continue to grow exponentially if their prey population is falling as a result of an ever-increasing wolf population. Even if the wolf population was given unlimited abiotic factors like unlimited water and space/shelter, the wolf population simply can't grow larger due to being limited by available food. The carrying capacity for that population is equally limited by abiotic and biotic factors.