US government has a special Visa Waiver Program for countries that meet its security guidelines. And today 38 countries are participating in the program. Objective of the program is to relax visa norms for participating countries. Visitors going to US on short trips are provided electronic visa instead of regular visa.
Visitors from VWP participating countries are provided USA ESTA Visa for entering into US territories without getting formal visa.It is for visitors that want to visit US for short time that is up to 90 days. Technically it is electronic authorization system that screens visitors before they are allowed to enter into the US territory. Advantage of electronic screening is that it reduces waiting time for visitors and also it helps in formal screening of visitors.
US gets the largest number of visitors in the world hence it has to handle a high pressure of incoming people. The VWP is drafted to reduce pressure from emigration authorities. A visitor with electronic visa can easily get entry into US territory as he has been screened for security and the visa shows that he poses no threat to the US. But the electronic visa is only screening and the permission is granted by authorities at the entry points.
ESTA application is available on US government website and also there are third-party sites that help in applying for electronic visa provided under VWP program. A nominal charge of $14 is levied by government but third-party sites add their a few dollars more as service charge to the government fee. Visitors are allowed to file their electronic visa applications through government site or from third-party sites.
Electronic clearance can be obtained within 24 hours but it is better you file your application before 72 hours of your flight. It is better to file your application in advance so that you have time to take the regular visa route, if you are denied ESTA. But there are little chances of your electronic visa application getting rejected. Take precaution while entering details like your name and passport number as you won’t get a second chance to apply for visa, if it is rejected.