...
If the customer pays by credit card, the user swipes the card and required details will be automatically generated. If the option has been allowed in the configuration settings, user can also manually enter the card details. User presses the process button, and if the transaction is approved, a receipt will be printed for customer signature and a second copy to be given to the customer. Once the transaction is complete, the application will go back to the normal sale window.
Details: 
Users can swipe the card, and customer's card information will be auto filled into the fields above. If they don't the physical card may be damaged, or the user can re-swipe the card. If the card is damaged based on the configurations and the users /wiki/spaces/user/pages/688276 they may be able to hand enter the card data, in which the * marks the mandatory fields.
...