What is the difference between a crow and a raven in Australia? Based on the distribution and physiology.

http://www.diffen.com/difference/Crow_vs_Raven

physiology, sorry can't help with distribution

The web page above gives a north American perspective, though both crows and ravens are in the genus Corvus.  There are four species of raven recognized in Australia and two native crow species.  While the crows may be very slightly smaller than ravens, you would need to have them side by side to appreciate it.  The Torresian crow occurs across the whole of northern Australia above the tropic, and some way below it in the west particularly.  It is notably heavier built than the Little crow, which occurs over most of Australia except the wettest eastern and northern parts.  Two of the raven species (Forest raven and Relict raven ) have very restricted distributions in the south-east of Australia; the Little raven also has a south-east distribution but occurs throughout Victoria and much of NSW and South Australia.  It is about the same size as the Torresian crow.  The Australasian raven is the largest corvid, and occurs in the south and east of Australia, but also in the sout west and in the drier parts of Queensland and the eastern parts of the Northern Territory, in desert and savannah habitat.  I am not aware of any physiological differences between crows and ravens in Australia, rather I think that European names have been applied to similar looking birds in Australia.