SKU

SKU stands for Stock Keeping Unit. It's the seller's internal ID for a specific configuration of a specific product, the level at which inventory is actually counted.

A red XL t-shirt and a red M t-shirt are two SKUs, even if they share a parent listing. If you have 5 colours and 4 sizes, that's 20 SKUs.

Robnu uses your SKU on every internal record, packing slip, vendor invoice, customer invoice, manifest line, deduction trace. When you graduate to an OMS for inventory, you'll bring the same SKU IDs with you; nothing in Robnu's data model needs to change.