The Crown is the state in all its aspects within the jurisprudence of the Commonwealth realms and their sub-divisions (such as Crown dependencies, provinces, or states), although the term is not only a metonym for the state, but also the reigning monarch.
A corporation sole, the Crown is the legal embodiment of executive, legislative, and judicial governance in the monarchy of each country. These monarchies are united by the personal union of their monarch, but they are independent states. The concept of the Crown developed first in England as a separation of the literal crown and property of the nation state from the person and personal property of the monarch. It spread through English and later British colonisation and is now rooted in the legal lexicon of the United Kingdom, its Crown dependencies, and the other 15 independent realms. It is not to be confused with any physical crown, such as those of the British regalia.
The term is also found in expressions such as "Crown land", which some countries refer to as "public land" or "state land"; as well as in some offices, such as Minister of the Crown, Crown Attorney, and Crown Prosecutor. Wikipedia