Cumulative discount is a type of discount where all the available discounts are applied on a particular ticket type.
If there is a flat discount created on a ticket and then a code discount is created and also if there is a bulk discount also then if Cumulative discount is enabled, then all the three discounts will be applied on the ticket.
Here, the biggest question is, which one is applied first or what is the sequence in which these discounts are applied? To answer this question, the sequence in which these discounts are created, it will be applied in the same sequence. If during the course of ongoing registration, if any of these discounts are edited, then the sequence of the discount applied would get changed as one of them is updated, hence the create date is updated.
The cumulative discount calculation also works in a particular fashion. The first discount is applied on the Base price, the next discount is applied on the discounted price and this process is continued till all the available discount types are exhausted.