WITHOUT PREJUDICE
"Private law is that part of a legal system which is part of the jus commune that involves relationships between individuals, such as the law of contracts or torts, as it is called in the common law, and the law of obligations as it is called in civilian legal systems. It is to be distinguished from public law, which deals with relationships between natural and artificial persons (i.e., individuals, business entities, non-profit organizations) and the state including regulatory statutes, penal law and other law that effects the public order.
In general terms, public law involves interrelations between the state and the general population, whereas private law involves interations between private citizens.
The concept of private law in common law countries is a little more broad, in that it also encompasses private relationships between governments and private individuals or other entities. That is, relationships between governments and individuals based on the law of contract or torts are governed by private law, and are not considered to be within the scope of public law."
http://en.wikipedia.org/wiki/Private_law
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"The original phrase "common wealth" or "the common weal" is a calque translation of the Latin term res publica ('public matters'), from which the word republic comes, which was itself used as a synonym for the greek politeia as well as for the republican (i.e. non-monarchical) Roman constitution (in legal theory still in force during the empire, see Principate).
The English noun Commonwealth dates originally from the fifteenth century and in different contexts indicates:
1. a political unit founded in law by agreement of the people for the common good;
2. a federated union of constituent states;
3. a republic;
4. a Co-operative Commonwealth is a society based on cooperative and socialist principles."
http://en.wikipedia.org/wiki/Commonwealth
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"Civil law could be:
* A a legal system based on the Justinian code prevailent in continental Europe, Central and South America, as well as Quebec and Louisiana.
* The area of law governing relations between private individuals.
* Laws imposed by the state as distinguished from laws inherent from nature."
http://en.wikipedia.org/wiki/Civil_law