• So far Contextual Selectors have only required the second item to be a descendant of the first

ol li {color:red}
<ol>
 <li>First
  <ul><li>Sublist item</li><li>Sublist item 2</li>
  </ul></li>
 <li>Second item</li>
</ol>

The inner list items are also descendants of ul so are coloured red

• A > operator indicates that the descendant must be a child of the parent

li {color:blue}
ul > li {color:red}

The inner list items are only descendants of ol so are coloured red