PayPal Payment Method and Order Status

I need a little help with regards to the payment method and order status:

I have set up a PayPal Sandbox testing accounts to test the PayPal payment gateway. A buyer checks out from the store, and arranges the payment via PayPal website(standard, pay on PayPal website). Payment is successful, and then the order in CS-Cart is showing “Open”.

As a store admin, how would I know whether the order has been paid or not? Is checking the PayPal account the only way to verify?

Also, in general, is there a relationship between the whether an online payment or offline payment is successful, and how that would impact the order status?

I am new to CS-Cart, and very much appreciate any help.

Best regards,