It's a non-immigrant visa for temporary workers granting them work permit in US.
Requires specialized knowledge in a work area & a bachelors degree.
Companies submit visa petition for its employees with US immigration department.
Cap is 65000 & an additional 20000 for those who have completed masters in US.
Lottery system in case more applications are received.
USCIS (US citizen & immigration services) starts to receive petitions by 2nd April for the fiscal year that begins on 1st Oct.
Once the petition is approved & selected, the applicant must schedule an interview with US embassy for stamping visa.
VISA is for 3 years which can be extended for another 3 years.
It's a multiple entry visa.
Spouse and unmarried children of H-1B VISA holders get H-4 VISA & allowed to stay in US under dependent category.
H-1B holders can apply for Green card which is a permanent residency card valid for 10 years & renewable. After holding Green Card for 5 years, professionals can apply for US citizenship.
Coming June, USCIS may curb work permit for H-4 visa holders.