A food chain is a straightforward linear sequence of organisms that illustrates the transfer of energy from one organism to another.

It begins with a producer, typically a plant, and culminates with a top predator. For instance, in a grassland ecosystem, a possible food chain could be represented as:

$\text{grass} \rightarrow \text{grasshopper} \rightarrow \text{mouse} \rightarrow \text{snake} \rightarrow \text{hawk}.$

In this chain, each organism relies on the preceding one for energy. The removal of any single organism can trigger a ripple effect throughout the entire ecosystem, impacting various species and their interactions.

Conversely, a food web offers a more intricate depiction of the feeding relationships within an ecosystem. It highlights the interconnectedness of multiple food chains. In a food web, an organism can participate in various food chains simultaneously. For example, a grassland food web might encompass a diverse array of producers, such as grasses, shrubs, and trees, alongside herbivores like rabbits and deer, as well as predators such as foxes and coyotes. Each organism in this web depends on others for energy, and the elimination of one species can lead to cascading effects across the ecosystem.

In conclusion, a food chain represents a simple linear flow of energy among organisms, while a food web provides a more complex illustration of the feeding relationships within an ecosystem, showcasing the interconnections among different food chains.