Budgerigars are native to Australia, but over the years they have been bred to different standards in other parts of the world.
The 'pet' type of budgerigars (also known as "American Budgies" only in america ) are a small bird, usually up to 180mm in length. These birds are more commonly found in pet stores.
A larger breed of Exhibition budgerigars (also called "English Budgies" or "Show or exhibition Budgies") were originally developed in England. Theses birds were developed from Australian budgies but due to lack of breeding stock breeding them back to related birds increased their size and type. Exhibition budgies are much larger, 220 - 240mm in length and appear to have have larger 'boofy' heads. The appearance is more about feather than bone structure. This type of budgerigar is normally bred by dedicated exhibition breeders that belong to a budgerigar club.
Both types make great pets. Click here to see pictures of the different varieties Member's Budgies