Dragonflies (Suborder Anisoptera) dragonflies are larger, have large eyes that touch or almost touch, two pairs of strong transparent wings which are dissimilar, the hindwings broaden near the base to the connecting point to their bodies. They rest with their wings open and held horizontally.
Damselflies (Suborder Zygoptera) damselflies are small and delicate-looking, and have eyes that are separated. They rest holding their wings together above the body or held slightly open above. The hindwing of the damselfly is essentially similar to the forewing.
Both however have similar life cycles. Females lays their eggs in or near water. The larval or immature odonates (meaning member of the Odonata) are called nymphs or naiads using internal gills to breathe, and using extendable jaws (Have you seen the movie Alien?) to catch other aquatic insects or even tadpoles and fish. The larvae of large dragonflies may live as long as five years, or two months to three years in smaller species. When the the larva is ready to metamorphose into an adult, it climbs up some emergent plant at night. Then the skin splits at a weak spot behind the head and the adult dragonfly crawls out of its old larval skin, waits for the sun to rise, pumps up its wings and flies off to feed on flying insects like mosquitoes and flies. In the adult stage, larger species of dragonfly can live as long as four months.