Original: The order Psittaciformes (parrots) contains two families of parrots, the cockatoos and the true parrots.
Simplified: The true parrots are about 330 species of bird belonging to the Psittacidae family, one of the two families in the biological order Psittaciformes (parrots). The other family is the Cacatuidae (cockatoos) which are also parrots, but not classified as true parrots.