The commenting system creates the equivalent of a discussion board for each post. Users can post comments to discuss any node that has had comments enabled. The ability to use this mechanism is believed to be an important part of involving members in a community dialogue.
An administrator can give comment permissions to user groups, and users can (optionally) edit their previously entered comment, assuming no others have been posted since. Users can be granted control over the chronological ordering of posts (newest or oldest first) and the number of posts to display on each page. Comments behave like other user submissions - filters, smileys and HTML that work in nodes will also work with comments. The comment module provides specific features to inform site members when new comments have been posted. For example, when you have subscribed to a node, replies to your comments will cause you to get an email to draw you back to the site.
Each node that has comments enabled will have a hyperlink which reads 'Add new comment' under the node display. Each comment has a subject, which defaults to the subject being comment on. When a comment has already been entered, the options (delete, edit, and reply) are provided under the comment text.
Administrators can find additional information about the commenting system here.