What is JSX, ES5, ES6 blog article fig2

fig2.html

<div class="map-wrapper">
  <p>Here's a map!</p>
  <div id="map"></div>
  <script>
    var map;
    function initMap() {
      map = new google.maps.Map(document.getElementById('map'), {
        center: {lat: -34.397, lng: 150.644},
        zoom: 8
      });
    }
  </script>
</div>