The Subclass 600 Visitor Visa is a traditional visa for tourists, business visitors, or family visits, and is required by nationals not eligible for ETA or eVisitor. It supports stays up to 3, 6, or 12 months and requires a full application with supporting documents. In contrast, the Electronic Travel Authority (ETA, Subclass 601) is for citizens of visa-exempt countries, is quick and digital, valid for multiple entries over 12 months, and allows stays up to 90 days each visit