This is an electronic travel authorization system used to gain travel authorization to the United States. There are certain countries that fall under a visa waiver program, meaning that you do not need a visa to enter the US to visit. In that case you use the ESTA system. The countries that qualify in the VISA waiver program include Andora, Australia, Austria, Belgium, Brunei, The Czech Republic, Denmark, Estonia, Finland, France, Germany, Hungary, Iceland, Ireland, Italy, Japan, Latvia, Lichtenstein, Lithuania, Luxembourg, Malta, Monaco, The Netherlands, New Zealand, Norway, Portugal, San Marino, Singapore, Slovakia, Slovenia, South Korea, Spain, Sweden, Switzerland, and The United Kingdom. Some people from these countries may still need a visa depending on their personal circumstances, such as having a criminal record. To determine if you can enter the US without a visa, you must submit an ESTA application. To apply for an ESTA, you must access the US Customs and Border Patrol website and fill out a form. You enter personal information and submit the form and you will receive one of three responses. "Travel authorized" means you have been approved and can enter the US without a VISA. "Authorization pending" means an automatic decision could not be made and you must log onto your application within 72 hours for a response. "Travel not authorized" means that you were not approved for an ESTA and you have to apply for a visa. If you are approved you will receive an application number and an expiration date which is 2 years or when your passport expires. You don't need this information to travel but you must have the passport you applied with. The customs officer will scan the passport and see your ESTA application information. ESTA is only for those people visiting the US.
Have an iPhone? Check out all 200+ new features coming in iOS 13.