In a legal context, "de jure" is contrasted to a "de facto" practice, where, for example, the people obey a contract as though there were a law enforcing it, yet there is no such law.
In a legal context, "de jure" is also translated as "concerning law". A practice may exist de facto, where, for example, the people obey a contract as though there were a law enforcing it, yet there is no such law.