Sharepoint - SQL Server

SQL Server provides unified storage by storing all user and config data with exception of search indices and site definitions (XML files) 

• Configuration Database – info about web farm configuration
  
• Content Database (Site) –sites, lists, list items, and documents
  
• Profile Database – user profiles and audience targeting
  
• Services database – search configuration info
  
• Single Sign On (SSO) – credentials to access other line of business apps 
  

Some tables from one application in your database:

dbo.Sites - Stored Site Collection

dbo.Webs - Stored Each Individual Site in the Site Collection

dbo.Lists - All the lists within all sites collection

dbo.AllUserData - Stored list's items

dbo.AllDocs - Stored documents and information about