What is a contract?

A contract is fundamentally defined as an agreement between two or more parties that creates mutual obligations enforceable by law. This definition encompasses both written and verbal agreements, as long as there is a clear understanding and acceptance of the terms by all involved parties. Contracts typically involve an offer, acceptance, and consideration (something of value exchanged), which reinforces the legal aspect of their enforceability.

The other options do not accurately represent the comprehensive nature of a contract. A unilateral commitment refers to a situation where one party makes a promise without the expectation of a return promise from the other party, which does not constitute a contract in the traditional sense. A verbal agreement can indeed form a contract, but stipulating it as "only" verbal overlooks the possibility of written contracts, which are often more enforceable. An individual promise without a witness lacks the necessary elements of a contract, as it does not involve two or more parties nor does it require formal witnessing to be considered valid. Therefore, the definition of a contract as an agreement between two or more parties is the most complete and accurate understanding of the term.