It was the first multicultural empire in history. It was also the first very large empire. Because of this the Empire had to develop ways of running effectively. Roads were built over great distances. Standardize currency. Localized governing systems (i.e. satrapies). It was also the first time Asian powers attempted to invade Europe.
it refers to the power of the Judiciary of a country. the judiciary is the system of courts which interpret law and provide justice to its masses.