What is main distinction between the doctrine of \’Res Judicata\’ and the rule embodied In Order II Rule II of the CPC?

Both the doctrine of Res judicata and rule embodied in O-2, R-2 are based on the rule of law that no man shall be vexed twice for one and the same cause.

From the bare reading of both the provisions following important distinction between doctrine of Res judicata and the rule embodied in O-2, R-2 of C. P. Code clearly come out.

Looking to the provision of O-2, R-2 of C. P Code it’s become clear that O-2, R-2 of C. P Code is based on the salutary principle that a defendant should not be twice vexed for the same cause by splitting the claim and the relief, to preclude the plaintiff from so doing it is provided that if he omits any part of the claim or fails to claim a remedy available to him in respect or that cause of action he will thereafter be precluded from so doing In any subsequent litigation that he may commence if he had not obtained the prior permission of the court, but rule does not preclude a second suit based on a distinct cause of action.

On other hand principle of Res judicata only applies to the subsequent suit in such circumstances when a competent court has decided the former suit between same parties on the same point of issue. [Inacio Marrins V/s. Narayan Hari reported in AIR 1993 SC 1756]