If you want to vacation or visit to the USA, you need to get USA Visa before you travel. If you need to enter USA for business, even in a very short time then you will need to apply esta visa.
US Customs ESTA Apply online for visiting to the USA. Your trip include the business of conventional business meetings, negotiations and conferences. You have an option to go USA through ESTA Immigration USA.
Electronic System for Travel Authorization, application may be submitted online here e-visa-usa.