The term "alien" can have different meanings depending on the context in which it is used. In the realm of immigration and nationality law, an "alien" typically refers to a person who is not a citizen or national of the country in question. In this context, it pertains to someone from a different country or a foreign national residing in a particular country.
On the other hand, in popular culture and discussions related to extraterrestrial life, the term "alien" commonly refers to a being from another planet or celestial body. It is used to describe hypothetical intelligent life forms that may exist beyond Earth.
So, to summarize, "alien" can refer to either a person from a different country or a being from another planet, depending on the context in which it is used.