When you click to join a course on the course page, you will be asked to login to enroll. You will see a page like this:

You will then be send an e-mail to confirm your address.
Registering gives you the benefits of keeping track of your progress in the courses you follow and enables you to receive certificates of completion for each successfully concluded final quiz.
We only collect data necessary to support you following our courses, and will not use these in any other way. For more information on what data we collect and how we use it, read our Privacy Policy.