According to Wikipedia, In the field of inventory management, a stock keeping unit or SKU is a distinct item, such as a product or service, as it is offered for sale that embodies all attributes associated with the item and that distinguish it from all other items. 


The SKU Code is basically the unique product code you assign to each product to identify it easily. 


IMPORTANT:

The SKU Code is the Backbone Of Your Inventory, and it is crucial that your SKU code is the same across all marketplaces, to make best use of Browntape's Multi Channel SKU mapping, which can decrease your workload by a big chunk. 


Each marketplace calls it by a different name. Below is a list of the different names given to SKU codes.



Marketplaces SKU Names
Ebay Custom Label
Snapdeal SKU Code
Shopclues Merchant Ref Code
Amazon Seller SKU
Flipkart Seller SKU ID