Understanding MVC & SQL Server
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I am following some tutorials and i'm completely lost on how MVC/SQL Server connect. 

I am going through a tutorial and the person mentions that the following code automatically creates a database for me:

    <connectionStrings>
    <add name="LibraryContext" connectionString="Data Source = |DataDirectory|Library.sdf" providerName="System.Data.SqlServerCe.4.0"/>
  </connectionStrings>

Can you please tell me what the above code does in a simple and detailed way. What |DataDirectory|Library.sdf does and what SQLServerCe..etc...all of it.. PLEASE & THANK YOU!