Can someone please shed some light on what a Bill of Exchange is and how this instrument can be used/what for/who issues them. Thanks

An unconditional order issued by a person or business which directs the recipient to pay a fixed sum of money to a third party at a future date. The future date may be either fixed or negotiable. A bill of exchange must be in writing and signed and dated. also called draft.

also see: http://www.businessdictionary.com/definition/bill-of-exchange-BOE.html

all depends on the creditworthiness of the participants

Generally used in trade financing