Sneaker culture
SKU
Also called style code, SKU code, product code
A SKU is the code that identifies one exact shoe, down to the colourway. Two colours of the same silhouette are two SKUs, with two codes and two lots of stock. SNKRS prints the code on the product page; Nike's own name for it is the style code, and people use the two interchangeably.
In use: Same silhouette, two colourways, two SKUs: two release times, two sizes to pick and two separate entries.
One code, one exact shoe
A SKU identifies a single product variant, not a model. The same silhouette in two colours is two SKUs with two codes, sometimes two release dates, and always separate stock. SNKRS shows the code on the product page under the name and the colourway, which is how people confirm they are looking at the release they think they are.
Nike’s own word for it is the style code. In sneaker conversation SKU has won, and the two are used to mean the same thing.
Where the distinction bites
Searching by name gets you the wrong pair surprisingly often, because retailers and resale listings reuse a model name across years and colourways. The code does not move. If you are checking a retail price, a release date or a resale listing, match the code rather than the name.
The same logic runs through the Laced app. Each SKU on the calendar is its own release to select and its own size to choose, and one profile holds one entry per SKU. So picking two colourways of one shoe is two selections, not one, and the second one is not a duplicate.