This opens up a window from which you can open new discussions in the Forum with your entire class or restricted to the instructor and TAs of the course. The email will already contain the name of the course and the location of the page on which you clicked that button.

This is the preferred way for you to ask questions or comment on the course materials. You are strongly encouraged to use this rather than to simply fire up your email program and write directly to the instructor. If you have a question about an assignment, use the button at the bottom of the assignment page. If you have a question about some code appearing on a page of lecture notes, use the button at that bottom of the page containing that code, and so on.

After all, you want me to respond quickly and accurately to your message. Experience has shown that students tend, however, to omit important context info (such as what course they are in, which assignment they are working on, etc.). An instructor may be teaching several different courses in a semester. If some of these are web-courses, the instructor may have students progressing through the course at different rates, So if you send the instructor a message that omits this kind of context information, one of two things is likely to happen:

So it's really in your own best interest to streamline the communication process as much as possible. And, while we're on the subject, you might want to think about how to phrase your question or comment to get the quickest and most accurate response.