Discussions are used in courses to facilitate collaboration for assignments and homework as well as encourage debate. To access the course discussion area, click on the Discussions link from the navigation menu on the left.

The main page will display all the discussion topics that are currently active. Topics with the latest activity will be at the top while old topics will be at the bottom.
Some instructors may have made a discussion topic an assignment which will count for points. This will be indicated by the footnote as shown in the screenshot below.

View and Reply to Existing Topics
To view and reply to existing topics, click on the link for the topic that you wish to view and/or reply to.
Click on the Write a reply... box to open the text editor and write a reply to the post.
For threaded discussions where posts are nested, clicking on the individual contributor's post will allow you to reply directly to a reply instead of the original poster's post.

You can collapse or expand all posts in a long discussion as well as jump to the next unread reply via the links in the panel to the right.

Start New Topics
To create a new topic, click on the Start a New Topic button from the content panel on the right.

Give your topic a title and body. If you wish, you may attach a file to the new topic. When you are ready to publish it, click the Add New Topic button.

Other users may now view and reply to your discussion topic.