The ETA system was introduced in 1996, providing authorization to travel to Australia and is electronically linked to your passport. While checking in at the airport for your Australian-bound flight, the check-in staff can electronically confirm that you have the authority to board the flight to Australia. The Australian ETA is available to citizens of over 50 countries.
The ETA is an electronically-stored authority for travel to Australia for short-term tourist or business visits and for applicants outside Australia. It replaces the visa label or stamp in a passport and reduces the need for travelers to visit an Australian Embassy. The Australian ETA allows the holder to travel to Australia as many times as required within the validity period of 1 year after issued. The maximum length of each visit is 90 days Per Entry.