A spider is any of more than 51,500 species of eight-legged arachnids belonging to the order Araneae. Unlike insects, spiders have two main body sections rather than three and eight legs rather than six.
Nearly all spiders are predators, typically consuming insects and other arthropods. Some actively hunt, while others use silk to construct webs for trapping prey. Given their global abundance, spiders are among the most important predators of insects.