De jure is an expression from the Latin words meaning "in law".
It is often used in contrast to de facto (which means "in fact", or "in practice") when talking about law, governance, or technique. When talking about law, "de jure" is used to describe what the law says, and "de facto" is used to describe what actually happens.
Examples
This means that legally the territory of Abkhazia is a part of the country of Georgia, but that it is in effect independent.
The de jure name of Bill Clinton is William Jefferson Clinton. This is his name according to official records. His de facto name is Bill Clinton because this is what he is usually called.