Auslan
Auslan is the sign language used by the Australian deaf community.The word 'Auslan' comes from "australian sign language". It is not called ASL as that refers to American Sign Language.
It is related to British Sign Language (BSL) and New Zealand Sign Language (NZSL).
Auslan in relation to English
Auslan is a natural language, different from spoken or written English. Its (flexible) grammar and vocabulary often do not have direct English counterparts. English may be referred to as Auslan's host language, as the Deaf community, surrounded by English, inevitably draws from it. Signers make use of English words through fingerspelling. Some words are preferably fingerspelt even when there is an equivalent sign. Fingerspelling can also be used for emphasis, clarification, or (sometimes extensively) by English-speaking learners of Auslan. Some signs feature an English-word's initial letter (as a handshape from a manual alphabet) and use it within a sign. For example, the sign for "Canberra" resembles a "C" on a flagpole, while the sign for "team" uses "T" handshapes, but is otherwise the same as the sign for "group".
Unlike Auslan, Signed English was an attempt to artificially create a sign language with English grammar and English-like signs. It was used largely in education to encourage the deaf to learn English grammar, and is generally seen by the Deaf community as being contrived and unnatural. Signed English has now been largely rejected by Deaf communities in Australia. A small number of its signs have made their way into normal usage (i think?).
Written and recorded Auslan
Auslan has no written form. Transcribing Auslan is largely an academic exercise. Auslan dictionaries use either photographs or drawings with motion arrows to describe signs, or CD-ROMs containing short video clips. Auslan signers generally read and write in English. Video has been used to record stories and jokes (etc), as these especially lose a lot when translated to English."Dialects"
Auslan is a natural language, and varies somewhat between Australian states. Auslan dictionaries and increasing ease of travel within Australia has had an impact on bringing the dialects of Auslan together. There seems to be little drive for standardisation, however, as there is little difficulty in communication.