Which type of contract has performance of obligations that are correlative to one another?

A bilateral contract is defined by the mutual exchange of promises or obligations between parties. In this type of contract, each party's performance is directly related to the performance of the other party. For example, in a typical sales agreement, one party promises to deliver goods while the other promises to pay for them. The obligations are correlative because the fulfillment of one party's obligation triggers the responsibility of the other party to complete their obligation.

This characteristic of bilateral contracts contrasts with other types of contracts. In gratuitous contracts, for example, one party may provide a benefit without expecting anything in return, thus lacking the mutual obligation aspect. Commutative contracts involve an exchange where the performance and value of each party's contributions are predetermined and can be compared, but they do not necessarily involve a direct correlation in the way obligations are performed. Aleatory contracts are based on uncertain events and involve risk, where performance is contingent upon an event occurring, which distinguishes them from the direct reciprocal obligations seen in bilateral contracts.