The Comment module in Drupal allows users to comment on many types of site content, as allowed by the site administrator.
When Comment module is enabled, users can post comments to discuss a forum topic, a blog post, a book page, etc. Comments behave like other user submissions. Filters, smileys and HTML that work in nodes will also work with comments if configured accordingly.
As an administrator, you can specify the default comment settings for each content type. You can specify content permissions (for example, you can specify whether anonymous users can make comments). You can also specify whether comments are allowed for a specific node.
In Drupal 7 and later, you can also add new fields to comments.
You can also enable a Recent Comments block. For more information on enabling blocks, see Working with Blocks.
This section provides information on only a few of the many contributed modules that extend the core commenting functionality.