How does the barcode system works?

Question

Like how is there no overlap of barcodes at all? There’s are millions if not, billions of items around the world that have unique barcodes. Are they differentiated per country or something?

In: 503

Answer 1

Think of barcodes like landline numbers, with each number having an ‘area code’ and the number itself. There are databases out there that maintain the equivalent of telephone directories – the area code = manufacturer, phone number = exact product.

As others have pointed out, there are billions+ of numbers encoded by barcodes, the equivalent of billions of unique phone numbers.