Domicile is the country in which one resides legally. It is the legal residence of a person.
The phrase is often used only in law or related to law. In law, it refers to the legal permanent residence of a person. This could be the same or different than the hometown or even the country of which the person is a citizen. Only the locality, where the person is currently and legally staying is considered to the domicile.
A person can still be domiciled to one location, even if they have left it. In this case, usually the person has traveled out of town or country for a short period, or they may have moved somewhere else, but that move may not be permanent as of yet or the documentation for the move may not have gone through yet.
In corporate law, a corporation’s place of domicile is considered to be equivalent to its place of incorporation. However, recently it have been concluded that the “principal place of business refers to the place where corporations high level officers direct, control and coordinate the corporations activities.”