An arthropod is an invertebrate animal belonging to the phylum Arthropoda, which includes insects, arachnids, myriapods, and crustaceans. These organisms are characterized by their exoskeleton, segmented bodies, and jointed appendages. Arthropods are the largest group of animals on Earth, playing vital roles in ecosystems as pollinators, decomposers, and food sources for other animals. They exhibit a wide variety of forms and adaptations, enabling them to thrive in diverse environments.