There are two types of bank instruments: negotiable and non-negotiable. Negotiable instruments include cheques, bank drafts, bills of exchange, and promissory notes. Cheques can be open, bearer, order, or crossed for safety. Crossed cheques are not cashed over the counter and can only be deposited into the payee's account. Cheques can be dishonored for reasons like insufficient funds, discrepancies in amounts, or if reported lost or stolen. Bank drafts are similar to cheques but issued by a bank, guaranteeing payment from the drawer bank.