title: confusion about SQL Server Express and localdb
body: <p>I need to deploy a WCF service with a database on client machines. I am confused about SQL Server Express. I need to verify all of the following.  </p>
  
  <p>When attaching database files in the <code>App_Data</code> folder, do I still need to install SQL Server Express engine (Windows service) on client machines? </p>
  
  <p>There is a flavor called SQL Server Express <strong>LocalDb</strong>. That one does not need an engine (Windows service)? But I think it need a prerequisite installation of LocalDb.  </p>
  
  <p>Localdb is introduced with SQL Server 2012. There is NO localdb for SQL Server 2008. Correct? I could not find 2008 version on MS site.  </p>