Design refers to the features of shape, configuration, pattern or ornamentation which can be judged by the eye in finished products.
Design registration is used to protect the visual appearance of manufactured products.
A registered design gives you a legally enforceable right to use your product's design to gain a marketing edge. It also prevents others from using the design without your agreement. The protection you receive is only for the appearance of the article and not how it works. Australian industrial or commercial designs are administered by the Designs Office of IP Australia, a Federal Government organisation. You do not have to register your design to use it.