1 - A Cast, in particular the method of 'Casting' refer to any sculptural artwork resulting from pouring a liquid such as wet plaster or molten bronze into a mold and allowing it to harden. 

2 - A Cast, may also specifically refer to Plaster Cast used in an Art School.
A Cast is is a reproduction of a classical sculpture or may display the bones & muscles of a human. Art students draw casts to learn about shadow & tone, or anatomy. Casts are commonly called busts, although many full figure casts also exist.

The Julian Ashton Art School, Australia's oldest continuous art school has one of the largest collections of casts in Australia and students still draw from them today. The school's collection is represents an important part of Australia's art history and they are classified by The National Trust.