The most common way to obtain lawful permanent residency in the United States is through a petition filed by a family member. Under American immigration law, there are two categories of familial relationships; immediate relatives and preference relationships. The law places no limit on the number of visas available for immediate relatives. Therefore an immediate relative never has to wait for a visa; one is “immediately” available.
Preference relationships, on the other hand, are allotted only a limited number of visas each year. Since more immigrants apply than there are visas available, a backlog has developed. Therefore a preference relationship requires an immigrant to file a petition and then wait for a visa in order to immigrate to the United States. The length of this wait depends on the immigrant’s country of origin and the preference category of the relationship. Further information regarding this process can be found here – Priority Dates. The following are immediate relative relationships:
The following categories are preference relationship:
Once an immigrant has a visa available to him or her, they must then file to become a permanent resident. If the immigrant obtains his or her residency in the United States, the process is called adjustment of status. If the immigrant obtains their visa abroad at an American consulate, it is called consular processing.