An alias can be set on a product so that it is searchable in many different ways. For example, if a product with a sku of 811214 has a UPC of 813986006726 but I also want to search by the old UPC that the manufacturer used to use, the old UPC can be added as an alias. Multiple aliases can be set for one product.
An alias can be added to a product by clicking Aliases from the toolbox.
Alternatively, if you want to create an alternate product profile see ShadowProducts