Whats the difference between result and return

#1

whats the difference between result and return (urls)

#2

ResultURL is the URL on your web application that Paynow will POST any updates of the transaction status to (see documentation here) - this is server-to-server communication that the client will normally be unaware of.

ReturnURL is the URL on your web site that the client will be redirected to after they have finished making (or cancelling) their payment on Paynow e.g. a page thanking the customer for their business