title: What are Navigation Properties in Entity Framework for?
body: <p>I see in my EF diagram alot of these navigation properties but not sure what they are really for. Like I see in lots of my tables I have aspnet_Users properties.</p>
  
  <p>What are these for? Do they help for joins? or what?</p>
  
  <pre><code>Error 2
  Error 3007: Problem in Mapping Fragments starting at lines 1201, 1423: 
  Non-Primary-Key column(s) [Field2] are being mapped in both fragments 
  to different conceptual side properties - data inconsistency is possible 
  because the corresponding conceptual side properties can be independently 
  modified.
  </code></pre>