Did you notice the addition of the word "restore" in the title of this section? Hopefully you did, as there is an important difference between restore and recover when it comes to Oracle. Restore is putting back the copy of the object (datafile, controlfile, spfile, archivelog) to a specific location. Recover is applying all of the transactions located in the online or offline (archived) redo and online undo segments to bring the database to a consistent state.
Consistency is where the checkpoint change numbers, for all datafiles agree with the checkpoint SCN of the database. That is your basic goal when doing database recovery. It is important to remember because anything that interrupts this process may result in lost transactions. Consistency is also important for the controlfile (it has its own checkpoint SCN), as Oracle takes a snapshot (read-consistent) of the controlfile if you back up the database when it is either mounted or open. The...
