Immediate Relatives of US Citizens:

Green card granted to foreign nationals who are the spouses, children, or parents of a U.S. citizen.

Unmarried Sons/Daughters of U.S. Citizens:

Green card granted to foreign nationals who are the unmarried sons and daughters (over 21 years old) of a U.S. citizen.

Spouses/Children of Lawful Permanent Residents:

Green card granted to foreign nationals who are the spouses, children, or unmarried adult sons or daughters of a lawful permanent resident in the United States.

Married Sons/Daughters of U.S. Citizens:

Green card granted to foreign nationals who are the married sons/daughters of U.S. citizens.