A food chain is a simple way to show how energy and nutrients move through an ecosystem. It starts with plants, which use sunlight to grow. These plants are called producers because they create their own food. Next, herbivores, or plant-eating animals, eat the plants. This step transfers energy from the producers to the consumers. After herbivores, we find carnivores, or meat-eating animals, that eat the herbivores. This continues up the chain, with larger carnivores eating smaller ones. Finally, when animals die, decomposers like fungi and bacteria break them down, returning nutrients to the soil and completing the cycle.