The difference between the portal generated invoice and the business invoice with a serial number is as follows:
The portal generated invoice: The portal generated invoice has the unique INR number, Ack No., Ack Date, and QR code, which are now applicable for above 5CR turnover and have already been uploaded electronically to the GST portal.
The business generated invoice: The business generated invoice has the details of the invoice header, customer information, invoice date, payment terms, description of products or services, subtotal, taxes, total amount due, etc.
You have to share both with the party.