When payments are integrated, it means there is a direct connection between your POS and payment terminal. As items and taxes are tallied up in the cart, that total is pushed automatically to the card reader where the customer completes their payment. Once the transaction is complete, the POS will register the payment and close the sale.
You can integrate payments with Shopify POS using a Shopify card reader. This increases accuracy and reduces the risk of errors that come with manually running transactions through an external terminal. And because payments are automatically registered in the app, there is no need to reconcile numbers between your POS system and payments provider at the end of the day.