Hi
An ESTA is not a visa but is a registration process for those eligible to travel under the visa waiver scheme. It is all very simple and the link below explains it.
https://esta.cbp.dhs.gov/esta/
Hope that helps.
I'll be transiting in the US (but planning to get of the airport) on my way in and out of South America and since I haven't been to the US in ages I am not familiar with how the ESTA process works. Any inputs? Thanks
