title: Explain ds.Tables[0].Rows.Count?
body: <p>I am a beginner, so don't be amused by my questions. I think
  <code>if (ds.Tables[0].Rows.Count &gt; 0)</code> is used to check if the dataset is empty. But what exactly <code>[0]</code> signify in this case? Can you explain this statement in a little more detail?
  And this one too.. <code>ds.Tables[0].Rows.Add(ds.Tables[0].NewRow());</code></p>