Within Teamwork Projects, a comment is a note that can be made on items within your projects.
Comments are specific to to a project item, such as tasks, milestones, files, notebooks, and links.
You can view and reply to comments on individual items, so that a discussion relating to the item is kept with the item itself.
You can see all comments across all project items, in the project's Comments tab:
You will find the 'Add Comment' icon when you hover over a particular project item, such as a task:
The comments icon will display a number representing the number of comments posted on that item. The icon will display green if you have any unread comments.
Hovering over the icon will give you a quick view of the most recent comment:
In the comments on-hover quick view, you can mark the comment as read, add a reply, or view all comments on the item.
Anywhere you see the comment icon, you can click it to show the comment editor, where you have the same formatting options, privacy and notify options as messages. These options will be affected by the privacy settings of the item you're commenting on.
Note: The comments tab can be enabled/disabled in the project's settings. Only project administrators and above can access the settings.
For more information see: Commenting on items