Body language
Every culture has certain 'typical' behaviours; ways of standing, moving, using hands, eyes, arms, nodding the head, etc. Usually there are meanings associated with these movements or gestures, and the meaning may be different in Australia from the meaning attached in your own culture.
In Australia, for example, it is usual to look someone in the eye when you are talking to him or her. Australians think that this shows directness, attention and sincerity; but in another culture, it may be considered as impolite or improper to do this. In some cultures, it is an insult if someone gives you something with the left hand - in Australia it makes no difference.
You will soon notice these differences when you start interacting with Australians. Similar observations are of course important anywhere else in the world. It is important that we learn to recognise, appreciate and respect difference as long as it is not offensive. If you are not sure ask people you know or staff at the University.