In SharePoint 2013—like the previous versions—with very few exceptions, all content is stored in SQL Server. This database structure is not much different from normal .NET web applications or previous versions of SharePoint. This SharePoint content is stored in over 20 databases that are created during the SharePoint installation. All of the default databases have specific purposes, for example, farm configuration information is stored in a configuration database.
The content itself is stored in multiple content databases. This is where only part of the farm needs to be recovered, typically a content database. An example is a corrupted site, or permanently overwritten document, forcing a restore operation. Simply put, the smaller the database to be restored, the faster the recovery time.
A secondary point to consider with overly-large content databases is the disk space during the restore process, as the standby server may have been provisioned...