Just like the order Odonata, dragonflies and damselflies, the order Lepidoptera has 2 similar but different groups, butterflies and moths. All lepidoptera are characterized by scaled wings and body, a proboscis or straw like moth, and a complete metamorphosis. There are nearly 175,000 estimated species of Lepidoptera and they are divided into nearly 175 families and superfamilies. There are different theries dividing these families up into which are butterflies and which moths because the differences between butterflies and moths are not cut and dry. For instance examine the two photos in this post. Both insects lack color, which is a trait that usually indicates moths. However they are both outside during the day and perched with their wings over their backs which are indicative of butterflies.
Both insects look very similar yet one is a butterfly and the other is a moth. Can you tell which is which? The best way to distinguish is to look at the antennae. Butterflies have clubs or widened sections at the end of their antennae where moths usually have either a straight or feathered antennae. With that hint can you tell which is which?