title: Logic behind data source=(local) in connection string
body: <p>I have two instances of SQL Server 2008 Express and one instance of SQL Server 2012 on my development machine. We're developing an ASP.NET MVC application and use the expression data source=(local); inside of our connectionString in Web.config.</p>
  
  <p>Now my question is what is the logic behind this expression? Which instance gets chosen and how can I change this behavior? </p>