Magpies belong to the family Corvidae, same as Crows. Ravens, Jays and others. As with crows they are believed to be one of the most intelligent to all animals. They are one of the few animals able to recognize self in the mirror test. The are classified as follows (Wikipedia):

Holarctic (black-and-white) magpies
Genus Pica
European Magpie, Pica pica
Black-billed Magpie, Pica hudsonia
Yellow-billed Magpie, Pica nuttalli
Korean Magpie, Pica sericea

Oriental (blue/green) magpies
Genus Urocissa
Formosan Blue Magpie Urocissa caerulea
Red-billed Blue Magpie, Urocissa erythrorhyncha
Gold-billed Magpie, Urocissa flavirostris
White-winged Magpie, Urocissa whiteheadi
Sri Lanka Blue Magpie, Urocissa ornata
Genus Cissa
Green Magpie, Cissa chinensis
Yellow-breasted Magpie, Cissa hypoleuca
Short-tailed Magpie, Cissa thalassina

Azure-winged Magpie
Genus Cyanopica
Azure-winged Magpie, Cyanopica cyana

The Australian Magpie belongs to the family Artamidae of 20 species of crow-like birds native to Australia and nearby areas.
Subfamily Artaminae
Genus Artamus
Ashy Woodswallow, Artamus fuscus
Fiji Woodswallow, Artamus mentalis
White-backed Woodswallow, Artamus monachus
Great Woodswallow, Artamus maximus
White-breasted Woodswallow, Artamus leucorynchus
Bismarck Woodswallow, Artamus insignis
Masked Woodswallow, Artamus personatus
White-browed Woodswallow, Artamus superciliosus
Black-faced Woodswallow, Artamus cinereus
Dusky Woodswallow, Artamus cyanopterus
Little Woodswallow, Artamus minor
Subfamily Cracticinae:
Genus Peltops
Mountain Peltops, Peltops montanus
Lowland Peltops, Peltops blainvillii
Genus Cracticus
Black Butcherbird, Cracticus quoyi
Grey Butcherbird, Cracticus torquatus
Hooded Butcherbird, Cracticus cassicus
Tagula Butcherbird, Cracticus louisiadensis
Black-backed Butcherbird, Cracticus mentalis
Australian Magpie, Cracticus tibicen
Pied Butcherbird, Cracticus nigrogularis
Genus Strepera
Pied Currawong, Strepera graculina
Black Currawong, Strepera fuliginosa
Grey Currawong, Strepera versicolor