This document provides an overview of feeding relationships in ecosystems through food chains and webs. It begins by defining objectives and key concepts like producers, consumers, autotrophs and heterotrophs. Examples of food chains show how energy and matter pass from plants to primary and secondary consumers. Food webs illustrate how organisms can be involved in multiple feeding relationships. The document suggests that removing any population, like hawks in one example, can disrupt an ecosystem's food web and affect other species.