I'm in the same position of antonse - can you spell it out a bit more? Suppose I'm a student studying course X at institution Y with course textbook Z - I sign

I'm in the same position of antonse - can you spell it out a bit more? Suppose I'm a student studying course X at institution Y with course textbook Z - I sign up to Boundless, and what do I actually get? A summary of Z? Or something else?