Two groups of family-based immigrant visa categories, immediate relatives and family preference, are provided under the provisions of United States immigration law, specifically the Immigration and Nationality Act (INA). You can learn more about these two categories of immigrant visas on travel.state.gov.
To apply for an immediate relative or family preference immigrant visas, follow the steps on the Immigrant Visa Process on usvisas.state.gov. Once you have completed those steps, review the instructions given to you by the National Visa Center (NVC), along with the information presented on this website, for further guidance.