The Libraries configuration page allows administrators to enable/disable libraries and define global custom CSS/JavaScript used by all webforms. Watch video
The Webform module utilizes third-party Open Source libraries to enhance webform elements and to provide additional functionality. It is recommended that these libraries are installed in your Drupal installation's /libraries or /web/libraries directory. If these libraries are not installed, they will be automatically loaded from a CDN. All libraries are optional and can be excluded via the admin settings form.
There are several ways to download the needed third-party libraries.
Generate a composer.json file using drush webform:libraries:composer.
Execute drush webform:libraries:download, to download third-party libraries required by the Webform module. (OSX/Linux)
Execute drush webform:composer:update, to update your Drupal installation's composer.json to include the Webform module's selected libraries as repositories.
Download and extract a zipped archive containing all webform libraries (6.1.x or 6.2.x) and extract the directories and files to /libraries or /web/libraries