The shrub layer is an important part of many ecosystems, providing valuable habitat and food sources for a wide variety of animals. Synonyms for this layer include the understory, the shrub understory, and the shrub tier. Other terms that may be used include the scrub layer, the brush layer, and the thicket layer. Each of these terms describes the same basic concept - a layer of vegetation dominated by shrubs that grows beneath the canopy of taller trees. By understanding and using these synonyms, it becomes easier to communicate about the various layers of vegetation in a given ecosystem and the roles they play in supporting biodiversity.