'Crow' and 'raven' are generic terms for birds of the genus 'Corvus'. 'Crow' is usually applied to the smaller varieties, 'raven' to the larger. nd they are very smart birds. Almost all are covered with black feathers, so its tough to tell individual species unless you get a really good picture. IF you've ever been to the outback in Alaska, you know what a raven is - they is HUGE!, at least twice as big as the common crows we have here in the SoCal mountains.