The H1-B Visa is an employment-based non-immigrant Visa that allows US companies to employ foreign workers on a temporary but fairly long basis. It’s basically a work permit issued for a specialty occupation and requires theoretical and practical application of a specialized knowledge. Moreover, it requires the employee to have obtained a Bachelor’s degree or its equivalent.
Since US Green card application procedures are more time-consuming and cumbersome, most companies prefer using H1-B Visa to allow employees to stay on for long-term assignment in the US. Individuals are not entitled to apply for an H1-B Visa- it’s the employer who has to petition for the acceptance of the employee. The employer must offer a job and apply for the H1-B Visa with the US Immigration department.
The total stay is limited to 6 years- the initial approval being only for three years. On request for extension, the Visa can be approved for three more years. However, an H1-B Visa is eligible for application for Green Card or permanent residence in US. Also, the spouse and unmarried children under the age of 21 of the Visa holders are allowed to stay in US for the same duration as the H1B Visa.
There’s a limit (cap) to the number of H1-B Visas that can be made available each year. This limit changes very often depending on the political scenario at the time.