The SKU stands for Stock Keeping Unit. The SKU number is a VITAL piece of information to every store this is Combined with the UPC number.

It not only provides information about the items cost, but also about the number of items in the store, the number on back order and the number that can be purchased from other stores in the chain.

If vendors do not have SKU and UPC numbers, they would have no idea the amount of items they carry, or what they are spending or earning on that product and their profit margin would be impossible to track.