Who is a spider and an insect?

 Spiders are not insects. Insects fall under the class Insects while spiders fall under the Arachnida class. An insect has six legs, two compound eyes, three body parts ( head, thorax, and segmented abdomen ) , two antennae, and generally four wings.

                                                       ( This picture is captured by myself )

Unlike insect, spider do not have antennae. Antennae are joint appendages that are mounted to an insect's head. These are used not just to feel, but also to taste and smell. Spiders also lack wings, and therefore cannot fly.

A  spider is in a group of Arthropods called arachnids.