title: What is the difference between role=dialog and role=alertdialog?
body: <p>According to the <a href="https://www.w3.org/TR/wai-aria-1.1/" rel="noreferrer">WAI-ARIA specification</a> both roles should have:</p>
  
  <ul>
  <li>Focus on first focusable element</li>
  <li>User should not be able to leave dialog</li>
  <li>Should have proper <code>aria-label</code> set</li>
  <li>Should be used to interrupt flow and should require to take some action e.g. to click a button or to type something</li>
  </ul>
  
  <p>The only difference I see is that <code>alertdialog</code> should have <code>aria-describedby</code> set.</p>
  
  <p>This leads me to a question. Whats the practical difference between <code>role=dialog</code> and <code>role=alertdialog</code>? When shall we use one or another?</p>