The Drupal 8 Quicklink module enabled faster subsequent page loads on your Drupal site. It does this by prefetching links during idle time. This means as you browse your Drupal site, this module will be pulling down the html for any links that are in the current view port. This makes the next page load much faster.
The module adds additional features and configuration options so you can fine tune the experience to fit your Drupal 8 site.