Comments in Drupal

Drupal has a pretty robust comment system. You can set up basic commenting, threads, anonymous commenting, sorting of comments, and more all with the core Comment Module included in a basic Drupal installation.

Turning Comments on and Off
Drupal has comments turned on by default. You turn the comments on and off by enabling and disabling the comment module.

Comments Menu (in the Content management section)
This is where you set up most of the options available for comments.

Published Comments
The first thing you'll see is all of the published comments within your site. From here you can unpublish any comment, or you can delete them outright.

Approval Queue
Next to this tab is the Approval queue. This is where all the comments are that have been submitted, but not yet approved by you. Just check the comments you want to approve and those comments are now published.

Settings
The settings tab is where you can set the way the comments are viewed. This is divided into two parts;:Viewing Options, and Posting Settings

Viewing Options
The viewing options control how the comments are posted. Some of the options include a threaded list, a flat list, and subject only. You can also sort the comments by newest first, or oldest first.

The comment controls allows the viewer to set these options themselves.

Posting settings
The posting settings control more of what is included in the comments as opposed to what is shown.

Anonymous commenting
This setting allows you to set various options for anonymous users who want to leave comments. You can tell Drupal to force anonymous users that in order to post a comment, they must leave there name and email. This does not give them a username and password to access Drupal as a user. So they are still anonymous to Drupal.

Comment Subject Field
Instead of having a user fill out a subject for a comment, you can force Drupal to use the title of the node as the subject for all comments.

Preview comment
You can set that the user is required to preview their comment before they post, or if they can post directly without previewing.

Location of comment submission form
This sets the option of where the comment submission form is located, on a separate page, or below the post of comments.

Access Control
You also have access control with comments. From here you can control what roles can see, post, administer, and post without approval. From these access controls, you could let anonymous viewers read the comments and post new comments, but without approval if you wanted.