A green card grants a foreign national the right to live and work in the United States for an indefinite period of time. There are a number of ways to qualify for a green card. A spouse or family member may sponsor you for lawful permanent residency, and you can obtain a green card through a sponsorship from an employer.
The U.S. Department of State also holds an annual green card lottery, with 50,000 green cards available. You may also be able to obtain as green card as a person seeking asylum in the United States or have special status as a religious worker or foreign medical graduate.