It depends on how long you will stay in the United States and the main reason of your trip.
Depending on the length of your stay:
ESTA allows you to stay in the United States for up to 90 days. If you want to stay for more than 90 days from the date of arrival to the United States; you must apply for a visa.
Depending on the reason for your stay:
ESTA is the perfect document for you if you are travelling as a tourist, for a short medical stay, for a language or specialization courses (less than 18 hours per week), or if you transit to another country.
In addition, in case of a business trip, to sale or purchase a property, to participate in a trade fair or conference, and also for signing documents/contracts, ESTA is the ideal travel authorization.
However, if the purpose of the trip is to find a job, start studying at a college or university in the United States, or settle permanently, you will be required to apply for an appropriate visa to your case.
Even if you enter the United States on a private jet, you will still need to apply for a B1 or B2 visa. If you have ever been refused entry to the United States, for the reasons provided by law, the system will recognize you as ineligible, and you will then need a visa to re-enter the United States.
The ESTA cannot be extended, does not guarantee residence or citizenship, and does not allow you to apply for a Green Card (permanent residence in the United States) or other types of visas.