The Visa Waiver Program removes the requirement of Consular processing in some situations to promote United States tourism. The procedure is replaced with an online application system.
What a "Visa" Really Is
When a foreign national planned to travel to the United States the tradition was to apply for a Visa at the United States Embassy that had geographical jurisidication of their residence. In many countries this requirement still exists.
A Visa is permission given by the US for a foreign national to travel to a United States port of entry and to be inspected by US Customs and Border Patrol. After successful inspection, the national can enter the United States with certain rights and limitations.
These rights and limitations vary based on the circumstances of the proposed travel and the Visa that you apply for governs your rights and limitations while you are in the United States.
In certain countries, and depending on the nature of the proposed visit, no visa application is required to be able to come to a United States port of entry and enter after a successful inspection by Customs and Border Patrol.
What this means is that if your proposed travel is consistent with the following checklist, you can travel to the United States without a formal application and interview process at your US Embassy or Consulate. This means that your requirement to apply for a Visa is "waived."
Checklist for the Visa Waiver Program
You must be a national of one of the following countries;
Andorra, Australia, Austria, Belgium, Brunei, Czech Republic, Denmark, Estonia, Finland, France, Germany, Hungary, Iceland, Ireland, Italy, Japan, Latvia, Liechtenstein, Luxembourg, Lithuania, Malta, Monaco, Norway, the Netherlands, Portugal, San Marino, Singapore, Slovakia, Slovenia, South Korea, Spain, Sweden, Switzerland, United Kingdom, New Zealand
Your stay in the United States is 90 days or less.
You are granted authorization by ESTA.
ESTA is the Electronic System for Travel Authorization. Think of this as an electronic, online system of tracking and recordkeeping which retains the administrative benefit of Visa application procedure, but passes the ease on to the traveler.
Remember that you will still be subject to inspection at the US Port of Entry and part of our Border Protection is to make sure that you are eligible to enter the United States. ITo learn more about the eligibility requirements, consult an Attorney, the Department of State, or US Customs and Border Patrol.
Remember, the rights and limitations of your travel are the same as a Tourist "B" Visa, and your stay is limited to 90 days.From the author: Do I need a Visa?