Individuals coming from those countries that have visa waiver program approval status will be able to visit the country without needing a visa. Travelers will benefit from an easier process by applying online. Qualified travelers will find it easy to apply via the Eligible Countries for ESTA page.
Do ESTA Eligible Countries Change Over Time or Stay Fixed?

The list of ESTA eligible countries is dynamic in nature as opposed to being static. The list depends on the USA’s Visa Waiver Program, which continues to evolve according to the changing political and security ties, as well as the economic stability of that country. When countries satisfy the security requirements and have a non-immigrant visa refusal rate of less than 3%, then such countries are added to the list; recent examples are Qatar and Romania.
What Is the Validity Period of ESTA for Eligible Country Citizens?
The validity period for an Electronic System for Travel Authorization (ESTA) is two years from the date of issuance, but it may end sooner if your passport expires, whichever event occurs first. Within this validity period, qualified individuals can enter the United States as many times as they want through the Visa Waiver Program without being required to apply again. However, each entry will be limited to a period not exceeding 90 days.
What Are the Reasons ESTA Applications Get Rejected for Eligible Countries?

Although you might be from an eligible Visa Waiver Program country, you should be aware that there are many other reasons why your USA ESTA Application could get denied. The first and most prevalent reason is the existence of mistakes in the application process, which can include typing mistakes or even incorrect passport details. Other important reasons why your application denied include having a criminal background, previous visa rejections, or staying longer than the allowed ninety days during previous trips.