Also called OMS, order management
An order management system, or OMS, is where every order lives from the moment it is placed until it is delivered or returned. It pulls in orders from all your channels, reserves stock for them, and tracks each step: accepted, picked, packed, dispatched, delivered.
Without one, orders sit in WhatsApp chats, marketplace dashboards and a notebook, and some get missed. Stock is not held for open orders, so two channels can sell the same unit. Deadlines slip because nobody sees them in one place.
A shop with 60 orders a day from four sources can see at 3 p.m. which 7 must leave in the next two hours. Available-to-promise is stock on hand minus what is reserved for open orders. Okount's order screen brings every channel into one list with dispatch deadlines.