Paypal Basic allows you to receive payments using Paypal. Once a user has created an order he gets a Paypal button which he has to click in order to pay. This button is available in the order confirmation page as well as on the order tracking page. It'll disappears once the order is marked as paid.
the email address of the receivers account
if set to production you can start earning real money. Otherwise the sandbox mode is used. Make sure you entered a sandbox receiver.
Send confirmation mail before payment completed
If you want to send the order confirmation mail after the payment is complete, use this option. By default, the mail is send when the order is created. Setting this option to NO will result in sending the order confirmation mail if the order is marked as paid. There will be no additional payment complete-mail.