OCP 1Z0 053 193

193.What is the purpose of the recover command? (Choose all that apply.) 
A. Recover database datafiles from physical disk backup sets. 
B. Recover required incremental backups from physical disk backup sets. 
C. Recover required archived redo logs from physical disk backup sets. 
D. Apply incremental backups to recover the database. 
E. Apply archived redo logs to recover the database. 
Answer: BCDE 

http://docs.oracle.com/cd/E11882_01/backup.112/e10643/rcmsynta2001.htm#i84135

Prerequisites

All redo or incremental changes required for the recovery must exist on disk or in SBT. If RMAN needs to restore incremental backups or archived redo log files during recovery, then you must either have automatic channels configured or manually allocate channels of the same type that created these backups.