Welcome to the most comprehensive research guide for those seeking information on United States. immigration Green Card policies. Immigration Green Card is another name for a permanent resident visa. It is an identification card that provides proof of the individual’s lawful and permanent residency status in the United States. A Green Card affords the individual the right to live and work permanently in the United States. In addition, a United States. immigration Green Card means that the holder is legally registered according to United States immigration laws. Green Card refers to the official card issued by the U.S government to lawful permanent residents (immigrants) as evidence of their authorization to live and work in the United States. The Permanent Residence Card. It is commonly called the Green Card not because of its current color, but because of the original color of the card many years ago. U.S. immigration Green Card is the first step in becoming a naturalized American citizen