An alien is "any person not a citizen or national of the United States" and is synonymous with noncitizen . Refugees and Asylees

Refugee admissions are governed by different criteria and numerical limits than immigrant admissions. It indicates the proportion of foreign born residents is not as large as during earlier periods, but is approaching historic levels at the turn of the last century. Figure 2 illustrates that the sheer number—32.5 in 2002—has more than doubled from 14.1 million in 1980 and is at the highest point in U.S. history. Naturalization

Another tradition of immigration policy is to provide immigrants an opportunity to integrate fully into society.
Congress typically considers a wide range of immigration issues and now that the number of foreign born residents of the United States—32.5 million in 2002—is at the highest point in U.S. history, the debates over immigration policies grow in importance. As a backdrop to these debates, this report provides an introduction to immigration and naturalization policy, concepts, and statistical trends. It touches on a range of topics, including numerical limits, refugees and asylees, exclusion, naturalization, illegal aliens, eligibility for federal benefits, and taxation. This report does not track legislation and will not be regularly updated.