There are several ways to sponsor family members to obtain permanent residency in the U.S.
Adjustment of Status (AOS): If the spouse and/or children are here in the United States, they may qualify to apply for permanent residence (a green card) without returning to the home country. The process includes filing an application with USCIS and proving your relationship is bona fide (real).
In most cases, your spouse will be able to receive work authorization from USCIS within a few months. Depending on your spouse’s status, he or she may also qualify for an advance parole document to allow travel outside the U.S. while the adjustment of status application is pending.
Consular Processing: A spouse and/or children abroad can apply for a visa at a U.S. Consulate in their home country.
Fiancée/Fiancé Visa: You can bring your fiancé(e) into the U.S. by sponsoring them for a K-1 fiancé(e) visa. Entry is allowed for 90 days to get married. After that, an application for adjustment of status (AOS) can be filed here in the U.S.
K-3 Visa: The K-3 visa was initially created to allow your spouse and his or her minor children to live in the United States while your immigrant petition was being processed at USCIS. It also allows them to obtain employment authorization while they are waiting.