What do you understand by the term Revision?

Revision is governed by the provisions of section 79 of Civil Procedure Act. It is the act of Superior Court to exercise its supervisory powers over Subordinate Courts for instance: The High Court has power under section 79 of the CPC to call for the record of any case which has been decided by any Court subordinate to it and in which no appeal lies thereto. The High Court can do so on its own motion or on application by any aggrieved party. 

Note: Grounds for Revision under section 79(1)(a) to (c) are: 

(a). If subordinate Court exercise jurisdiction not vested in it by law; or 

(b).If subordinate Court fails to exercise jurisdiction vested in it; or 

(c). If in exercise of its jurisdiction the Court act illegally or with material irregularity.