A non-immigrant (temporary) work visa allows foreign nationals to come to the United States to work for a specific period, often tied to a particular job or employer. The most common types of U.S. temporary work visas are categorized under nonimmigrant visas.
An Immigrant (permanent) work visa is an employment based immigrant visa that allows foreign nationals to live and work permanently in the United States. These visas are granted to individuals based on their skills, education, or job offer from a U.S. employer.