It can also be epitomized as follows: a collateral contract is one that induces a person to enter into a separate "primary" contract. For example, if X agrees to buy goods from Y that will, accordingly, be manufactured by Z, and does so on the strength of Z's assurance as to the high quality of the goods, X and Z may be held to have made a collateral contract consisting of Z's promise of quality given in consideration of X's promise to enter into the main contract with Y.