The literal meaning is a stamp placed in a foreign national's passport by an official at a U.S. consulate outside of the United States. All visas allow their holders to enter the United States within a certain period of time. Visas can be designated as either "immigrant visas" or "nonimmigrant visas." Immigrant visas are given to people who have earned U.S. permanent residence or a "green card." Nonimmigrant visas are given to people coming to the U.S. for a temporary stay. However, immigration law also sometimes talks about visas "becoming available," which refers not to the stamp itself, but to instances where a limited number of visas are given out each year, and people who want them must place themselves on a waiting list.