REDCAY
the difference is size. bith have a crest that comes up if the bird is exited and both come from australia.
the other differences between them are man made.
cockatoos are priced from $1000,00 to $20,000. and are rarely crossbred. minimume cage is a 2' X 2' with the cockatoo having he ability to stand outside the cage on a play pen or in my case a tree i made. they need to spread out and move about for health and vitality.
cockateils are cheap, anywhere from $10.00 up to whatever the traffic will bear for unusual colors.
because of this, cockateils are constantly crtoss bred to produce a more colorful and valuale bird
they eat about the same things and both can learn to talk. cockateils live about 15 to 20 years. the life span of a cockatoo can me the same as man. they can live 70 or more years.
my suggestion for a first bird is always a parakeet.
cheap, colorful, small cage, tame easily and learn to talk as well as any bird. if you find out you don't have the time or interest in a bird, you have a minimum investment, life span about 5 years.