The document discusses key aspects of negotiable instruments under the Negotiable Instruments Act 1881 including definitions of promissory notes, bills of exchange, and cheques. It provides details on their essential characteristics and how they differ. A promissory note contains an unconditional undertaking signed by the maker to pay a certain sum of money. A bill of exchange is an unconditional order signed by the maker directing payment of a sum of money. A cheque is a bill of exchange drawn on a specified banker and payable on demand.