This document summarizes different types of nematodes (roundworms), including intestinal and tissue nematodes. Intestinal nematodes discussed include Enterobius, Trichuris, Ascaris, Necator, Ancylostoma, Strongyloides, and Trichinella. Their life cycles and symptoms, methods of diagnosis, and treatments are described. Tissue nematodes mentioned are Wuchereria and Onchocerca.