The United States provides different types of visas to foreigners those who want to live permanently in the country and those who intend to visit temporarily for some purpose. For temporary visitors or non-immigrants, there is student visa, business visa, tourist visa, special visa for dignitaries and journalists, etc. People who want to live permanently in the country can avail immigrant visa or green card.
Foreigners who wish to work in the US on a temporary basis can also apply for H-1B visa. To be eligible for H-1B visa, a job offer from a US employer is essential. Unlike a student, tourist visa, the foreigners cannot directly apply for this visa. The prospective employer has to file a petition with the United States Citizenship and Immigration Services (USCIS). If the USCIS approves the petition then the foreign worker can be hired on H-1B visa.
Otherwise, foreigners can apply for other visas at the US embassy and consulate in their native country. It is very easy to get a tourist or business visa and it is issued in a few weeks. But there is no certainty that you will be provided the non-immigrant visa. Due to security reasons, your applications can be cancelled or process of issuing visa can be deferred. Hence, you may be called for another round of interview or provide additional information
For immigrants, the US State Department conducts a lottery in which it randomly selects 50,000 applicants from across the world to provide permanent residency visas or green cards. The administration will hold such lottery in 2007, for which it has short listed 82,000 people out of more than 5.5 million applicants. US government website www.UnitedStatesVisas.gov provides information on visa policies and procedure.
It is also important that you need to fill in your application form properly as many visa seekers get rejected due to improper filling up application forms.