Final answer:
Primary consumers, also known as herbivores or grazers in some cases, consume primary producers in ecosystems. They can be represented within the larger context of a food web and may include humans when they consume plant-based foods.
Step-by-step explanation:
Primary consumers are part of an ecosystem's structure and dynamics, characterized by their role in the food chain. As herbivores that consume primary producers such as plants or phytoplankton, primary consumers can also be referred to as herbivores, omnivores when including humans, or even grazers in specific contexts like grazing food webs. Additionally, in educational resources and scientific literature, primary consumers are illustrated within food web graphics, which depict the complex interactions and energy flow between different trophic levels. When humans eat plant-based foods, they act as primary consumers, and when they consume animals like cows, they occupy the role of secondary consumers. Certain animals, like the opossum shrimp, can function at multiple trophic levels, consuming both primary producers and primary consumers.