H-1B签证是美国的一种非移民签证类别，适用于具备专业知识和技能的外国专业人士，让他们能在美国从事专业性职业。以下是H-1B签证的详细解释：

  1. 专业性职业： H-1B签证适用于从事“专业性职业”的个人。专业性职业指的是需要在某一高度专业领域具备理论和实践知识的工作，并且至少需要拥有学士学位或相当水平的学历。专业性职业的例子包括工程、计算机编程、医学、会计等等。
  2. 雇主赞助： 要获得H-1B签证，外国专业人士必须获得一家愿意为其提供工作岗位的美国雇主的支持。雇主必须代表外国工作者向美国公民和移民服务局（USCIS）提交H-1B签证申请。
  3. 配额限制： 每个财政年度H-1B签证的发放数量受到限制。截至本写作时，普通配额为65,000个签证，额外的20,000个签证则留给拥有美国院校硕士学位及以上学历的个人。
  4. 劳工条件申请（LCA）： 在提交H-1B签证申请之前，雇主必须先从劳工部（DOL）获得经批准的劳工条件申请（LCA）。LCA证明H-1B工作者将获得该职位的现行工资，且其就业不会对美国工人的工作条件造成不利影响。
  5. 逗留期限： H-1B签证持有人最初可以在美国逗留最多三年，可延期至最多六年。在特定情况下，如获得批准的基于雇佣的移民申请（Form I-140）或成为H-1B豁免配额的受益人，可延长超过六年的逗留期。
  6. 双重意图： H-1B签证的一个优势是其“双重意图”条款，允许H-1B签证持有人在仍保持非移民身份的情况下，拥有移民美国的意图。这意味着H-1B签证持有人可以申请合法永久居民身份（绿卡），而不会影响其H-1B签证身份。
  7. 随行家属： H-1B签证持有人可以将配偶和未满21岁的未婚子女带到美国作为H-4随行家属。H-4签证持有人, 在没有EAD工作许可前，不被允许在美国工作，但可以就读学校或大学。

总之，H-1B签证是高技能外国专业人士在美国从事专业性职业的一种受欢迎的途径。该签证为有技能的工作者提供了在美国劳动力市场做出贡献的机会，并为他们在未来追求永久居留提供了可能性。

The H-1B visa is a non-immigrant visa category in the United States, designed for foreign professionals with specialized knowledge and skills to work for U.S. employers in specialty occupations. Here is a detailed explanation of the H-1B visa:

  1. Specialty Occupation: The H-1B visa is available for individuals working in “specialty occupations.” A specialty occupation is one that requires theoretical and practical application of a highly specialized body of knowledge and a minimum of a bachelor’s degree or equivalent in a specific field. Examples of specialty occupations include engineering, computer programming, medicine, accounting, and many others.
  2. Employer Sponsorship: To obtain an H-1B visa, foreign professionals must have a job offer from a U.S. employer who is willing to sponsor their visa. The employer must petition the U.S. Citizenship and Immigration Services (USCIS) on behalf of the foreign worker by filing the H-1B petition.
  3. Cap Limitations: There is an annual numerical cap on the number of H-1B visas that can be issued each fiscal year. As of the time of this writing, the regular cap is set at 65,000 visas, and an additional 20,000 visas are available for individuals who have earned a master’s degree or higher from a U.S. institution.
  4. Labor Condition Application (LCA): Before filing the H-1B petition, the employer must first obtain an approved Labor Condition Application (LCA) from the Department of Labor (DOL). The LCA attests that the H-1B worker will be paid the prevailing wage for the position and that the employment of the H-1B worker will not adversely affect the working conditions of U.S. workers.
  5. Duration of Stay: H-1B visa holders are initially granted up to three years of stay in the U.S., with the possibility of extension up to a maximum of six years. Extensions beyond six years may be possible in certain circumstances, such as having an approved employment-based immigrant petition (Form I-140) or being the beneficiary of an approved H-1B cap-exempt petition.
  6. Dual Intent: One of the advantages of the H-1B visa is its “dual intent” provision, which allows H-1B visa holders to have an intent to immigrate to the U.S. while still maintaining their non-immigrant status. This means that H-1B visa holders can apply for lawful permanent residency (green card) without jeopardizing their H-1B status.
  7. Dependents: H-1B visa holders can bring their spouse and unmarried children under the age of 21 to the U.S. as H-4 dependents. H-4 visa holders are not allowed to work in the U.S. if who does not have a EAD work permission, but they can attend school or college.

In conclusion, the H-1B visa is a popular pathway for highly skilled foreign professionals to work legally in the United States in specialty occupations. The visa offers opportunities for skilled workers to contribute to the U.S. workforce while having the potential to pursue permanent residency in the future.