If you are an immediate relative of a U.S. citizen, you can become a lawful permanent resident (get a Green Card) based on your family relationship if you meet certain eligibility requirements.
Immediate relatives are:
The spouse of a U.S. citizen;
The unmarried child under 21 years of age of a U.S. citizen; or
The parent of a U.S. citizen (if the U.S. citizen is 21 years of age or older).