One of the main benefits of having a restricted access Web site like the Discussion Board is that authorized users don't have to keep typing their names into form fields, such as when submitting an article to a discussion group, because the web server already knows who they are. Similarly, other users can be reasonably sure that you really sent the articles and postings attributed to you, and that someone else didn't pretend to be you when posting.
After you are successfully registered, your web browser will ask you to type in your username and password the first time you try to access the Discussion Board. The browser will remember this information for as long as it continues to run, so you can access any document in the Discussion Board without being asked for it again.