A legal tender is a form of payment recognized by law as valid for settling a financial obligation.
A bank note is a type of legal tender, as it is issued by a government and can be used to pay for goods and services.
A cheque and a travellers cheque are not considered legal tender, as they are simply a type of payment instrument that represents a promise to pay the amount written on them. They are not considered to be money in and of themselves, and must be first be cleared and processed by a bank before the funds can be accessed.
A goldsmith receipt is not considered legal tender, as it is simply a receipt for gold stored with a goldsmith, and does not have any monetary value in and of itself.