title: What does it mean when there is a comma inside an array declaration? e.g. float[,]
body: <p>I have some code I'm trying to understand while learning C#.  I do not understand what I even need to search Google for to get here, but the code is as follows:</p>
  
  <pre><code>float[,] heightAll = terData.GetHeights(0, 0, allWidth, allHeight);
  </code></pre>
  
  <p>Why does the array declaration have a comma in between the brackets?</p>