Letter of Credit: A letter of credit is a payment method where the buyer's bank guarantees payment to the seller upon presentation of required documents, providing security for both parties in an international trade transaction.
Bill of Exchange: A bill of exchange is a written order by one party (the drawer) directing another party (the drawee) to pay a specified amount to a third party (the payee) on a certain date.
Sight Draft: A sight draft is a type of bill of exchange that requires the drawee to pay the full amount of the draft upon presentation, as opposed to a time draft which allows for payment at a later date.