The Overseas Student Program (OSP) allows people who are not Australian citizens or permanent residents to study in Australia. A person who would like to study under this program must obtain a Student Visa before they can commence a course of study in Australia. To be granted a Student Visa you must undertake a registered course on a full-time basis.
If you wish to study in Australia for over 3 months, you need to apply for a Student Visa and satisfy specific visa criteria depending on the level of education you wish to complete, and your country of citizenship.