The term used to describe an organism that relies on others for food is heterotroph. Heterotrophs cannot produce their own energy or organic materials through photosynthesis or chemosynthesis; instead, they obtain their nutrients by consuming other organisms, including plants and animals. This group includes categories such as herbivores, carnivores, and omnivores. Understanding heterotrophy is essential in studies of food webs and energy flow within ecosystems, as it illustrates the interconnectedness of species and the balance of ecological systems.