The many relationships between the members of a community in an ecosystem can be described by food chains and webs.
Each stage in a food chain is called a trophic level, and the arrows represent the flow of energy and matter through the food chain.
Food Chains
Trophic levels can also be described as food chains or energy chains.
When a food chain is taken to its natural conclusion, humans are found at the end of it, meaning that we are dependant on an efficient transfer of energy along a food chain.
Every link in the chain acquires food and feeds on the link prior to it.
Each link is also consumed by the link that follows it.
Food chains are the process whereby energy that is trapped in carbon compounds is transferred through an ecosystem.
Food Webs
Most animals do not rely upon a single food source and within a single habitat many food chains will be linked together to form a food web.