Difference between commonwealth and state governmemts?

Four of the constituent states of the United States officially designate themselves Commonwealths: Kentucky, Machusetts, Pennsylvania, and Virginia. This designation, which has no constitutional impact, emphasizes that they have a "government based on the common consent of the people" as opposed to one legitimized through their earlier Royal Colony status that was derived from the King of Great Britain. In common parlance, notwithstanding, people do not make the distinction between state or commonwealth.