title: Why should you use the <label> tag and 'for' attribute?
body: <p>You can label an input field with a <code>&lt;label&gt;</code> tag like this:</p>
  
  <pre><code>&lt;label for="username"&gt;Username:&lt;/label&gt;
  &lt;input id="username" name="username" type="text"&gt;
  </code></pre>
  
  <p>But why?</p>
  
  <p>Is it effective for SEO? Or browser rendering? Or better support for mobile or other devices?</p>