The Alien Registration Number, shortened to A-Number, is a very important number the U.S. Citizenship and Immigration Services (USCIS) uses to identity you. This nine-digit number can be found on the front of your Green Card. All Lawful Permanent Residents are issued this number as soon as they start the Green Card application. This number is necessary for all contact with USCIS.
Adjustment of Status is the name of the Green Card application process for people who already live in the USA with a nonimmigrant visa. For example, foreign students living in the USA with an F-visa can proceed with an Adjustment of Status if they win the Green Card Lottery. In this case, the visa-holder can stay in the USA and adjust the status of their nonimmigrant visa to an immigrant visa.
Green Card applicants are required to prove that they have enough financial means to emigrate to the USA. An affidavit of support is a document completed by a relative or friend. The document is a promise to financially support the Green Card holder.
Age out refers to the time when a child is no longer eligible to qualify for a Green Card. The child of a Green Card Lottery winner must be under the age of 21, as defined by US immigration law, to apply for a Green Card.