There are two ways in which the U.S. classifies foreign visitors: non immigrant and immigrant.
Non-immigrants are foreign-born individuals who are permitted to enter the United States for a limited period of time, and are given only temporary (non-immigrant) visas. Examples of non-immigrants are students, tourists, temporary workers, business executives, and diplomats.
A legal immigrant is a foreign-born individual who has been admitted to reside in the United States as a lawful permanent resident (LPR). LPRs are given immigrant visas, commonly referred to as “green cards”.