A case break, or broken case, happens when a distributor opens a case to sell part of it: a few heads of lettuce from a case of 24, or two bags from a case of six. Small customers often need less than a case, and selling partial cases can win their business.
The cost is in tracking. Once a case is opened, inventory is part sealed cases and part loose units, pricing needs a markup to cover the handling, and counts get harder. A system that only knows whole cases forces the floor to keep the loose units on paper.
In APFoodz partial cases can be stocked, priced and sold, including online.