From e-Learning Documentation
The Chat tool allows for synchronous communication for participants online. All participants have the ability to post at any time. There are no controls that allow for instructors to moderate the conversation or block certain users, but can delete an inappropriate message. Conversations are recorded and can be viewed at a later date by all participants, even those who were not part of the Chat.
When you click on "Chat Room" in the left menu bar, you will be brought to the Main Chat Room that is provided for all users. You will see a list of users who are currently logged into the course.
To enter a message, type your post into the "Enter chat message" at the lower part of the screen. Hit Enter or click Add message to post your comment. All comments appear in the order in which they were posted and identified by the person's name.