When posting tuition fees, a multi-class discount will discount tuition fees based on the number of classes taken. The discount can be calculated using the total classes taken by one student in a family (student level discounting) or using the total classes taken by all students in a family (family level discounting).
For classes that have a Billing Method of By Class Fee, a multi-class discount is defined using a Tuition Discount Rule. The Discount Rule can be created as only a multi-class discount, or it can be added in combination with a multi-student discount using a combination rule type.
See the Manage Discount Rules (Tuition Billing Method By Class Fee) section of Help articles for more details and examples.