Stands for "Stock Keeping Unit," and is conveniently pronounced "skew." A SKU is a number or string of alpha and numeric characters that uniquely identify a product. For this reason, SKUs are often called part numbers, product numbers, and product identifiers.
SKUs may be a universal number such as a UPC code or supplier part number or may be a unique identifier used by a specific a store or online retailer. For example, one company may use the 10 character identifier supplied by the manufacturer as the SKU of an external hard drive. Another company may use a proprietary 6-digit number as the SKU to identify the part. Many retailers use their own SKU numbers to label products so they can track their inventory using their own custom database system.
When shopping online or at retail stores, knowing a product's SKU can help you locate the exact product at a later time. It will help you identify a unique product when there are many similar options, such as a TV model that comes in different colors, sizes, etc. If you know a product's SKU, you can typically locate the product online by typing the SKU in the online retailer's search box. If you visit a retail store and have questions about product you saw in an ad, knowing the SKU will help the salesperson find the exact product you are asking about. SKUs are typically listed in small print below the product name and are often preceded by the words "SKU," "Part Number," "Product ID," or something similar.