There are wide range of tourist visas, but the most common are:
Tourist Visa(600):- Normally lets you stay in Australia for up to 12 months. Your intention must be only a visit. You are not allowed to study for more than 3 months and work in any form. You must have sufficient funds to support yourself throughout the visit including return airfare.
Electronic Travel Authority (subclass 601) visa:- This is an Electronic Travel Authority that is available to only certain passport holders. This gets decided in less than 1 day but an agent might be needed for the application. All you need is be outside Australia for this visa to be approved.
Work and Holiday (subclass 462) visa:- If you are between 18-31 and want to holiday and work in Australia and hold the eligible country passport, you will be eligible for this visa. You need gazetted educational qualifications and functional english for this visa.