To strengthen the security of travel to the United States under the Visa Waiver Program, requirements to travel visa-free have been enhanced. Nationals of Visa Waiver Program countries will still be eligible to travel without a visa but will have to obtain an approved travel authorization prior to their travel to the United States.
The Department of Homeland Security and the United States Customs and Border Protection have provided a secure public Web site with an automated form for you, or a third party, to complete in order to apply for a travel authorization. Once you enter the required biographic, travel, and payment information on the secure Web site, your application is processed by the system to determine if you are eligible to travel to the United States under the Visa Waiver Program without a visa.
The Electronic System for Travel Authorization (ESTA) is an automated system used to determine the eligibility of visitors to travel to the United States under the Visa Waiver Program (VWP) and whether such travel poses any law enforcement or security risk.