Energy enters the ecosystem.

Energy primarily enters the ecosystem through producers (autotrophs), such as grasses, shrubs, or trees, which convert sunlight into chemical energy via photosynthesis.

This energy is then transferred to primary consumers (herbivores), like grasshoppers, beetles, or caterpillars, when they feed on the producers.

Secondary consumers (carnivores or omnivores), such as spiders, birds, or lizards, obtain energy by preying on primary consumers. Tertiary consumers, like hawks or snakes, then feed on secondary consumers.

A food chain illustrates a single pathway of this energy transfer (e.g., plant $\rightarrow$ grasshopper $\rightarrow$ bird). A food web shows the complex network of interconnected food chains, demonstrating multiple feeding relationships and the overall energy flow within the ecosystem.