A food web is a the feeding connections between organisms in a biotic community. Both energy and nutrients flow through a food web, moving through organisms as they are consumed by an organism above them in the food web. A single path of energy through a food web is called a food chain. In food webs arrows point from an organism that is consumed to the organism that consumes it.

Each organism within a food web can be classified by trophic level according to their position within the web. Depending on an organism's location in a food web, it may be grouped into more than one of these categories. Energy and nutrients move up trophic levels in the following order:

  1. Primary producers
  2. Primary consumers
  3. Secondary consumers
  4. Tertiary and other high-level consumers

Example of a food web: