A Parent Visa allows parents of eligible individuals to live in Australia. Eligible individuals include Australian citizens, holders of permanent residence visas, and certain New Zealand citizens. It is a permanent visa so you can work and live in Australia without time restrictions.
There is a limited number of Parent Visas available each year. A queuing system is therefore in place for applicants who meet the requirements. Those requirements include getting a sponsorship from your child. You then have to pass a balance of family test. This test involves demonstrating that most of your children live in Australia, or that more live in Australia than in any other country. A Contributory Parent Visa is also available. It is more expensive, but it can usually be obtain quicker.