Most species of moths are active at night (which means they are active at night), but there are dull (active during dusk) and diurnal (active during the day) species. Moths can be distinguished from a butterfly in several ways.
Most butterflies are brightly colored wings. Nocturnal moths on the other hand are usually plain brown, gray, white or black and often with a zigzag or rotating pattern that helps disguise them as they rest during the day. Yet many day-flying moths are brightly colored, especially if they are toxic. Some butterflies are also plain colored, like white cabbage butterflies.
Most moths are active at night (sleeping during the day and active at night) or dull (especially active during dusk) while most butterflies are diurnal (active during the day and rest at night). However there are exceptions, including the diurnal and spectacular Gypsy moths 'Uraniidae' or 'Sunset Moth'.
In general, they are the main visual differences between butterflies and moths, but the ones you remember most are that they are general rules and do not apply to all moths and butterflies. The similarity between the two is actually much greater