If you are the citizen of any country other than Australia and New Zealand, you will need a visa (or in some cases an Electronic Travel Authority) to visit Australia.
On a standard visitor visa you can stay up to 3 months from the date of entry. The visa is for multiple travel and can be used to enter Australia for 1 year from the date of issue. You are not permitted to work on this visa. You can also apply for a long stay visa. This is usually granted for stays up to 6 months.
Applications are generally processed within 24 hours.
If you are eligible to enter Australia on an ETA if you meet the following conditions:
you hold a passportapproved for ETA
you visit to Australia is for -
a convention or conference, or
a short term project or event requiring a high level of skill;
you will not work in Australia if you hold a tourist ETA;
you will not stay in Australia for more than three months;
you are in good health and have no criminal convictions.