The system is spread across many templates and custom post types, and so can be fully customized and tweaked.
The tabs area allows the user to quickly jump between the course content, course outline, and support material pages.
The breadcrumb navigation situates the user so they don't get lost in the course, and also allows them to jump to the course outline or first page of a section.
The badge counts show how many people are taking the course, how many are viewing the current section, and how many have ever completed the current section.
The badges remind the user they are connected to something bigger, so that even when taking a self-serve course they can feel part of a community.