A course can have a public page that displays what the course is about and how much it may cost or what prerequisites must be met to start the course. You can edit and view this page in your course settings under "Edit public page".
Enabling "Hide this course from public" will make this page non-public if you want to share the course only with private share links, for example.
Courses on teachr can be "active" on one side, i.e. "published". A course is then displayed for all your learners.
However, you can make further settings to hide or show the course for or from a specific audience.
See Public Visibilty to hide or show the course from the public.
With this function you can prevent users from enrolling in your course on the public page. Enrollment is then only possible if a user is a member of your virtual campus that you have manually added to your virtual campus.
If you want to make the course available only to a specific target group and use your public page for marketing purposes activate this feature. Create a Public invitation link in the course settings "Manage course participants". You can send this invitation link to your specific target group or share it on your social media channels with certain restrictions.
You can block access to this course, even for users who are enrolled on your virtual campus, by using the function Block Course for registration.