SharePoint 2013 may be installed and configured using either SQL Server 2008 R2 or SQL Server 2012. Many times SharePoint Administrators and SharePoint Developers overlook SQL Server in a SharePoint environment. It is there, it functions, and it's a black-box to many. SQL Server is essential to a productive SharePoint farm as that's where 90% of the content, configurations, settings, etc. are stored. Without SQL Server, there is no SharePoint. This guide explores the management of content databases. You may find other SharePoint database guides in Steve's SharePoint 2013 Solution Series or get them all together in The DBA's Guide to SharePoint 2013.