An herbivore is an organism that mostly feeds on plants. Herbivore range in size from tiny insects such as aphids to large, lumbering elephants. Herbivore are a major part of the food web, a description of which organisms eat other organisms in the wild. Organisms in the food web are grouped into trophic, or nutritional, levels.
From: https://education.nationalgeographic.org/resource/herbivore/