A more thorough explanation:

An immigrant visa is a legal document issued by the U.S. government for foreigners who want to live permanently in the United States. To apply for an immigrant visa, a foreign citizen must submit a petition to the United States Citizenship and Immigration Services (USCIS) by filling out Form I-130. There are different types of visas available for different circumstances.

• If a U.S. citizen wants to bring their spouse to live with them in the United States, they can apply for the IR1 or CR1 visa.
• If the spouse is still waiting for the approval of Form I-130, they can apply for the K-3 visa.
• Other types of immigrant visas include those for family members, employees, and refugees.

These examples illustrate how immigrant visas are used for different situations, such as reuniting families or allowing skilled workers to live and work in the United States.

After submitting the petition, the applicant must provide financial documents and complete an online application. They will also need to attend an application interview. A relative or employer may sponsor the application, as instructed by USCIS.

According to the Report of the Visa Office 2020, 4,013,210 immigrant visas were issued in 2020.