H1B is a kind of non-immigrant visa in the United States, which is suitable for professional workers sponsored by employers. The H1B visa allows foreigners to work in specific professional fields in the United States, and requires applicants to have relevant academic qualifications and professional skills. The employer needs to demonstrate that it cannot find suitable native employees in the United States and therefore needs to hire the foreign national. Applicants need to go through an employer-initiated application process and submit relevant documents such as qualifications, employment contracts and job requirements. H1B visas usually have a certain duration, initially 3 years, which can be extended up to 6 years. H1B visa is one of the important ways for foreign professionals to come to the United States for employment.