How does Sophia.org work? What's the not graded part and graded part?

[Duneranger]

I'm not exactly sure how Sophia works. Like what's the graded part and what's the not graded part? How many attempts can you make at the graded part if you don't score high enough to get credit before you have to pay again, stuff like that? I would appreciate it if someone can help me understand Sophia. Thank you.

Sophia.org does an excellent job explaining what each class entails, what pass/fail is, milestones etc. They have a student guide which you can download that explains everything.