An ISBN is the unique 13-digit identifier for your book; the barcode is just the scannable image of that number.
If you publish through platforms like Amazon KDP or IngramSpark , they can often generate and place the barcode on your cover automatically. Isbn Code Generator
Did you know that after buying your ISBN, you don't actually have to pay for the barcode? Many agencies like Bowker offer a barcode for an extra fee (often around $25), but as a self-published author, you can get this for free. An ISBN is the unique 13-digit identifier for