The Visa Waiver Program (VWP) enables nationals of certain countries (including Australia) to travel to the United States for tourism or business (visitor visa purposes) for stays of 90 days or less without obtaining a visa. Not all countries participate in the VWP, and not all travellers from VWP countries are eligible to use the program.
VWP travellers are required to apply for authorization through the Electronic System for Travel Authorization (ESTA), are screened at their port of entry into the United States, and are enrolled in the Department of Homeland Security’s Office of Biometric Identity Management.
For information on visa requirements, visit the US Embassy site via one of the following links:
Information on ESTA Visa Waiver Program