The flow of energy in a food web is commonly represented by trophic levels, which illustrate the hierarchical structure of energy transfer among organisms. Producers (such as plants) form the base, converting solar energy into chemical energy via photosynthesis. Primary consumers (herbivores) obtain energy by eating producers, while secondary and tertiary consumers (carnivores and omnivores) derive energy from consuming other animals. Arrows in a food web indicate the direction of energy transfer, making it clear how energy flows through an ecosystem.