Habitat structures refer to the physical features of an environment that provide shelter and resources for living organisms. These structures can include trees, rocks, soil, and water bodies, which create different niches for various species. For example, coral reefs serve as habitat structures in marine environments, offering protection and food for many fish and invertebrates. In terrestrial ecosystems, habitat structures like forests and grasslands support diverse wildlife by providing places to live, breed, and find food. The complexity of these structures, such as the layering of vegetation in a forest, influences the types of species that can thrive in a particular area, contributing to overall biodiversity.