A green card, officially known as a Permanent Resident Card, is the common term used to describe a permanent resident card. The green card allows its holders to live and work permanently in the United States.
This plastic photo identification card is given to persons who are legal permanent residents of the United States as proof that they are authorized to live and work in the United States. It serves as a U.S. entry document, enabling holders to return to the United States after temporary absences, and it proves their right to work in the United States. The green card expires after a certain number of years and must be renewed – but the holder's permanent residence itself does not expire, only the ability to prove it using the card.
See also: U.S. Citizenship and Immigration Services
[Last updated in February of 2022 by the Wex Definitions Team]