The document defines key terms related to weather, climate, ecology, and biomes. It describes weather as the short-term atmospheric conditions in an area, while climate refers to longer-term temperature and precipitation patterns. It also defines microclimates, the greenhouse effect, species tolerances and niches, resources, competitive exclusion, predation, herbivory, keystone species, and types of symbiotic relationships like mutualism, parasitism, and commensalism. Biome terms explained include canopy, understory, deciduous and coniferous forests, taiga, tundra, photic and aphotic zones, benthos, wetlands, plankton, and estuaries.