Easy, Fast and Reliable Oracle Backup and Recovery with RMAN

For many years, Oracle's RMAN utility (Recovery Manager) has been recommended to back up and recover Oracle databases. Of course there are other solutions available from third-party vendors, and in high-end environments, split mirror techniques are common for fast back up of databases. However, the rich set of features in RMAN, including some health checks like corrupt block detection, make this tool the preferred backup method for most databases.

But why is RMAN better than other methods? Why isn't it possible to just back up the devices or data files? What can ensure the ability to restore a backup - because that is, after all, why you back up your database in the first place.