Food chain and food web are important concepts in the study of human environment and ecology. They explain the relationship between living organisms and the transfer of energy and nutrients from one organism to another. Every organism in nature depends directly or indirectly on others for food and survival. These feeding relationships help maintain ecological balance and support life on Earth. A food chain is a simple and linear sequence that shows how energy passes from one organism to another through feeding. It begins with producers and moves through different levels of consumers. Producers are green plants and algae that prepare their own food by the process of photosynthesis using sunlight, water, and carbon dioxide. Herbivores or primary consumers feed on plants, while carnivores or secondary consumers feed on herbivores. Tertiary consumers are larger carnivores that feed on smaller carnivores. Decomposers such as bacteria and fungi break down dead organisms and return nutrients to the soil. An example of a food chain is: Grass → Grasshopper → Frog → Snake → Eagle In this food chain, grass acts as the producer. The grasshopper