An Oracle database running in ARCHIVELOG mode allows for point-in-time recovery and can reduce the amount of data loss if the database needs to be recovered for any reason. If a database has ARCHIVELOG mode enabled, the archived redo logs should be backed up and deleted on a regular basis. If you fail to back up the logs, they will be overwritten, making point-in-time recovery impossible.
An Oracle database running in NOARCHIVELOG mode can only be restored to the most recent full backup, and does not allow for point-in-time recovery.