A SKU (Stock Keeping Unit) is not the same as a barcode, but they are related. Here's how they differ:
SKU — A unique identifier assigned by a retailer to track inventory. It can be a combination of letters and numbers and is specific to a product's attributes, such as size, color, and style.
Barcode — A machine-readable representation of data, typically consisting of lines and spaces. Barcodes encode product information and are used to scan items at checkout or in inventory management systems.
In short, a SKU is an internal tracking code, while a barcode is a visual representation of that code (or other product information) for scanning purposes.