There are thousands of foreign workers, welcomed by the United States every year, in various occupations or employment categories. Every employment category for admission has different requirements, conditions and authorized periods of stay.
USCIS Español: https://www.uscis.gov/es/trabajar-en-los-estados-unidos
I-765, Application for Employment Authorization: https://www.uscis.gov/i-765
I-765, Solicitud de Autorización de Empleo: https://www.uscis.gov/es/formularios/i-765