Pionus is a genus of medium-sized parrots native to Mexico, and Central and South America. Characteristic of the genus are the chunky body, bare eye ring, and short square tail. They are superficially similar to Amazon parrots, but smaller, and in flight their wing-strokes are far deeper. Coloration is generally subdued yet complex compared to member species of the genus Amazona; under bright lighting, their feathers shimmer with iridescent brilliance. All species share bright red undertail coverts; the scientific name of one species, the blue-headed parrot, refers to this. Males and females are similar, with no notable sexual dimorphism.

Amazon parrots are parrots in the genus Amazona. They are medium-sized, short-tailed parrots native to the Americas, with their range extending from South America to Mexico and the Caribbean. Amazona is one of the 92 genera of parrots that make up the order Psittaciformes and is in the family Psittacidae, one of three families of true parrots. It contains about thirty species. Most amazons are predominantly green, with accenting colors that depend on the species, and they can be quite vivid. They feed primarily on seeds, nuts, and fruits, supplemented by leafy matter.