Does RMAN in Oracle only copy the archive logs? What happens to the active redo log in case of failure? If RMAN copy copies the archived redo logs when they are full, what happens to the current redo log in the event of a failure (hardware failure, etc.)?  Isn't there always an active redo log that is not an archive_log?
The first thing RMAN does it automatically perform an ALTER SYSTEM ARCHIVE LOG CURRENT to switch logfiles so that the active log at the point the backup was started will be included.

It doesn't do this in all backup situations, but this answers your question.