What is the difference between a barcode, SKU, and ISBN?

Barcode: is a scanable code which can be scan with the help of scanner to get informations from this code. it can be anything either EAN UPC ISBN or even any text or a quotation. so its a myth that barcode is only use for numbers but mostly its either EAN UPC or ISBN

SKU: Stock keeping unit which helps making it easy to find the stock and mostly its a text so we can easily understand and also create a barcode to scan sometime to get more details of the product faster.

Lastly ISBN is international standard book Number and it is used to publish a book whereas ean and upc are for other product identifiers.

hope it helps a lot. I buy cheap EAN UPC and ISBN to sell at Amazon ebay and websites from CodesForAmazon.Com – EAN UPC ISBN BARCODES