When you submit your ESTA application, the form and its details are kept on a secure database maintained by the United States government, and the border authorities will have electronic access to this data.
In order to confirm your identification and ensure that your passport hasn’t been reported stolen or misplaced, the information you submit in your application is checked against a number of databases. As a result, the external borders of the United States are more secure, and fraud and terrorism are less likely.
You should expect your application to be reviewed within 72 hours of submitting it. Aside from rare exceptions, the review process is often substantially shorter than the estimate. Make sure you complete out the ESTA application form thoroughly and accurately when you submit it for the shortest possible processing time.
You should get a response to your application through email after it has been evaluated.
The border authorities may examine your information on this database without you having to validate it when you enter the United States or board a transport to enter the United States.