title: Understanding Update and Delete Rules for Relationships in SSMS 2008
body: <p>I am confused about what means the update and delete rule in SQL Server 2008 Management Studio when we define foreign key constraints. I also did not find related help documents (e.g. F1 help).</p>
  
  <p>Here is the screen snapshot. Appreciate if anyone could describe what do they mean and recommend some related documents to read. :-)</p>
  
  <p><img src="https://i.stack.imgur.com/xQnC7.jpg" alt="enter image description here"></p>