In stock is the company's money. The difference between what is written in the system and what is physically on the shelf means loss.
Many apps record stock movements. The difference is not what you record, but how — who records, when, in what order, and who checks.
The principle that makes the difference is simple: the sender cannot confirm the receipt. One ships, another receives. The app compares the two operations and flags any differences.
The same principle applies everywhere in the module: shipping vs. receiving, purchase order vs. invoice received, scriptural stock vs. factual inventory stock. The difference is not hidden, it is resolved.
Stock flows involve several actors with distinct responsibilities. The salesperson orders the delivery of goods — decides what, how much and when. Logistics manages delivery — prepare, ship, confirm. Neither function can validate the operation of the other.