This visa lets parents of a settled Australian citizen, permanent resident or eligible New Zealand citizen live in Australia permanently.
You could apply for the Contributory Parent (Temporary) visa (subclass 173) before this visa. Applying for the temporary visa and then this permanent visa costs more but the costs are spread across the two visas over a longer period of time.
You could also apply for a Parent visa (subclass 103). The subclass 103 visa costs less than this visa but there can be long waiting times of up to 30 years.