Русско-англо-русский юридический словарь

Under the civil law system, cession is the equivalent of assignment, and therefore, is an act by which a personal claim is transferred from the assignor (the cedent) to the assignee (the cessionary). Whereas real rights are transferred by delivery, personal rights are transferred by cession. Once the obligation of the debtor is transferred, the cessionary is entirely substituted. The original creditor (cedent) loses his right to claim and the new creditor (cessionary) gains that right. (Wikipedia)

The act of cession is the assignment of property to another entity. In international law it commonly refers to land transferred by treaty. (Wikipedia)