
Just what is the difference between setting a grade condition in "Restrict availablity" and setting an activity completion condition whereby they have to have passed with a certain grade?
Under which circumstances would you use one and which the other?
For example: I want a student only to access a lesson after they have obtained 40% in a quiz.
I could set the grade condition to be 40% obtained in the quiz when I set up Restrict availablity in the lesson
OR
I could set the completion tracking of the quiz to be "require grade", then go to the gradebook and set the pass grade for the quiz to be 40% - then go to the Lesson and set activity completion condition for the quiz to "complete and passed"
I'm not sure I get the nuances here

Have I missed something out?