Restrict access determines how, when and by whom the activity may be accessed.
Activity completion – require students to complete a preceding activity
Date - Prevent access from/until a specified date and time.
Grade – Require student to achieve a specific grade in a specified section
Group – Specify the group access for the activity
Grouping – Specify the grouping access for the activity
User profile – Specify a specific user profile access
Restriction set – Create a set of the above restrictions that determines activity access.