The U.S. government may waive its right to exclude someone from the U.S. or its right to deport or remove someone from the U.S. The voluntary and intentional giving up of a right is called a “waiver.”
A “non-immigrant” visa is granted to those who wish to enter the U.S. for a specific period of time. There must be ties to another country of residence and there must be no intent to remain in the U.S. indefinitely. Examples are those who enter the U.S. to perform the ballet, participate in an athletic event, display their art, invest in a U.S. business, visit the Great Salt Lakes, visit relatives or friends and study.
A “refugee” is someone who seeks to enter, live and work in the U.S. because he or she will be persecuted or there is a well-founded fear of persecution in his or her own country. Persecution must be based upon the foreign national’s race, religion, social group, political opinion, or nationality