Roundworms, scientifically known as Nematoda, are a diverse group of elongated, cylindrical worms found in various environments, including soil, freshwater, and marine habitats. They play essential roles in ecosystems, such as decomposing organic matter and serving as food for other organisms. These worms can be free-living or parasitic, with some species causing diseases in plants and animals, including humans. A well-known model organism in scientific research is Caenorhabditis elegans, which has contributed significantly to our understanding of genetics and developmental biology.