- dissimilarity or discrepancy between the laws of different legal orders, such as states or nations, with regard to the applicable legal rules and principles in a matter that each legal order wishes to regulate.
- the branch of law dealing with the determination of the law applicable to a private-law matter, of the legal order having jurisdiction to adjudicate such a matter, and of the extent to which an adjudication in such a matter by another legal order is to be recognized and enforced locally.