title: What do commas and spaces in multiple classes mean in CSS?
body: <p>Here is an example that I do not understand:</p>
  
  <pre><code>.container_12 .grid_6,
  .container_16 .grid_8 {
      width: 460px;
  }
  </code></pre>
  
  <p>It seems to me that <code>width: 460px</code> is applied to all above mentioned classes. But why some classes are separated by a comma (<code>,</code>), and some just by a space?</p>
  
  <p>I assume that <code>width: 460px</code> will be applied only to those elements which combine classes in the way mentioned in the CSS file. For example, it will be applied to <code>&lt;div class='container_12 grid_6'&gt;</code> but it will not be applied to the <code>&lt;div class='container_12'&gt;</code>. Is this assumption correct?</p>