By default, Drupal provides the ability to add a comment as a field in the content type. Users with sufficient rights can then write comments.
This module makes this visually attractive and user-friendly. The responses are immediately displayed without having to refresh the page. As admin you can also view and approve the unpublished comments in the node. There is also some CSS on it.
If you allow anonymous comments, you can add comments as a guest via a name and email address.