Two (2) Aspects of Res Judicata
Res judicata is understood in two (2) senses: bar and conclusiveness. What is the difference between these two?
 Bar by Former Judgment. There is res judicata when, between the first case where the judgment was rendered and the second case where the judgment is invoked, there is identity of parties, subject matter and cause of action.
 Conclusiveness of Judgment. There is also res judicata when there is an identity of parties but not cause of action, the judgment being conclusive in the second case only as to those matters actually and directly controverted and determined, and not as to matters invoked thereon.