The budgerigar, also known as the common parakeet, shell parakeet or budgie, is a small, long-tailed, seed-eating parrot. Naturally, the species is green and yellow with black, scalloped markings on the nape, back, and wings. Budgies are bred in captivity with colouring of blues, whites, yellows, greys, and even with small crests. Juveniles and chicks are monomorphic, while adults are told apart by their cere colouring, and their behaviour.

A parakeet is any one of many small- to medium-sized species of parrot, in multiple genera, that generally has long tail feathers.