ESTA stands for Electronic System for Travel Authorization. It’s an automated system run by the U.S. Department of Homeland Security (DHS) that determines whether travelers from certain countries can enter the United States under the Visa Waiver Program (VWP).

It screens eligibility before you board. **Not a visa**; final admission is decided by CBP at the port of entry. Apply at least **72 hours** before travel. Approved ESTA is generally valid **2 years** (or until your passport expires) and covers multiple trips of **up to 90 days** each.

See also VWP Esta-Validity- Esta Land Entry onward return ticket form I94