Common law
The common lawso named because it was "common" to all the king's courts across Englandoriginated in the practices of the courts of the English kings in the centuries following the Norman Conquest in 1066. The British Empire spread the English legal system to its historical colonies, many of which retain the common law system today. These "common law systems" are legal systems that give great precedential weight to common law, and to the style of reasoning inherited from the English legal system.
Jus commune
Jus commune or ius commune is Latin for "common law" in certain jurisdictions. It is often used by civil law jurists to refer to those aspects of the civil law system's invariant legal principles, sometimes called "the law of the land" in English law. While the "ius commune" was a secure point of reference in continental European legal systems, in England it was not a point of reference at all. ("Ius commune" is distinct from the term "common law" meaning the Anglo-American family of law as opposed to the civil law family.)