Which of the following is NOT a type of alien?

Travelers are not classified as aliens in the same legal context as the other categories mentioned. Immigrants, non-immigrants, and undocumented migrants specifically refer to individuals who fall under various immigration statuses or movements within the framework of immigration law.

Immigrants are individuals who have the intention of residing permanently in a new country. Non-immigrants, on the other hand, enter a country temporarily for a specific purpose, such as work, study, or tourism, but they do not intend to stay indefinitely. Undocumented migrants are those who enter a country without legal permission or overstayed their visas, thus lacking proper immigration documentation.

Travelers generally refer to individuals who are not intending to settle in the country but are instead visiting for purposes such as tourism, business, or transit. While they may be classified in terms of visas or permissions required to enter a country, they do not fit the legal definitions of alien categories concerning residency and immigration status.