This document defines key vocabulary terms related to ecosystems, including environment, biotic, abiotic, habitat, population, community, ecosystem, niche, and biome. It lists examples of biotic factors like animals, plants, insects, algae, and microscopic organisms that make up ecosystems, as well as abiotic factors such as land, rocks, soil, air, sunlight, temperature, water, rainfall, and humidity. Abiotic factors determine what type of life an ecosystem can support.