Is the serial code the same as the barcode number?

My stepdad was telling me that if the serial number on a product is not the same as the numbers under the barcode, then it means that the product was switched out. I objected to that because what he was telling me, did not feel right.

I was trying to explain to him that they're not the same and the barcode and the serial code are not the same. I tried to tell him that the numbers under the barcode are there when you buy the product, and since products has numbers, it'll be able to legally identify the item, not the product itself. For example, electronics has serial numbers. You can literally get in contact with PlayStation, Xbox, Meta, etc and whatever product of theirs you had bought, and you claim that something is wrong with it, they may ask you for your serial number, which is like some kind of ultimate data-recover or account-recover. The barcodes are just for retail. A serial number is something that's personal and provides personal information.

He still insisted that both the product and the barcode are the same. I am trying to do a fact-check here and Google isn't giving me straight answers.

Is the serial code the same as the barcode number?
Post Opinion