title: What is the meaning of & in css styling in react js
body: <p>I have recently started learning to react js. I noticed that in some of the <code>style.ts</code> files &amp; has been used before the class declaration. </p>
  
  <pre><code>export const agGrid = {
      extend: [container],
      '&amp; .ag-theme-material': {
          marginTop: '2rem'
      }
  };
  </code></pre>
  
  <p>Can someone please help what is <code>&amp;</code> for? I think the framework used is <code>jss</code> that is visible from <code>package.json</code> file</p>