What is an SKU?
SKU is a unique identifier, meaning Stock Keeping Unit. This is the stock unit in a warehouse used to track availability and stock variations of an item to be sold. SKUs can be a variant of any item (e.g., Medium or Large size of a jogger pant). An SKU will be associated with a shipping category to determine the available shipping options for that SKU.
Commerce Layer is not a content management system. It is designed to take care of the transactional functionality of commerce, leaving all content management (including product, category, and catalog information) to the CMS of your choice. The link between the product information on the CMS and Commerce Layer is precisely the SKU code (that is linked to the single variant, not the generic "product."
An SKU consists of letters and numbers (either EAN code, UPC, or any other code format) like LSLEEVMM000000FFFFFFMXXX. SKU refers to an item's details, including variants and quantity data (e.g., a T-shirt, Red color, Nike brand, 0.5g, XL size, and five available pieces). An SKU identifies each product item's characteristics such as manufacturer name, brand name, style, color, weight, and size.
Each SKU can have one or more prices in one or more price lists and many stock items in many stock locations. The presence of a price and a stock item determines the SKU availability for a given market or customer group.