A contract is an agreement between two or more parties that creates mutual obligations enforceable by law. It typically involves the transfer of goods, services, money, or a promise to transfer any of those at a future date. The basic elements required for a contract to be legally enforceable are: offer, acceptance, consideration, and mutuality. Contracts are widely used in commercial law and form the legal foundation for transactions across the world. They are essential for establishing the foundation of professional relationships and governing the duties and responsibilities of the parties involved. Contracts can be oral or in writing, and they are enforceable by law. Contract law is generally governed by state common law and private law, and it may require some kinds of contracts to be put in writing and executed with particular formalities for enforceability. The court interprets the contract as a whole and according to the ordinary meaning of the words, and when the intention of the parties is unclear, courts look to any custom and usage in a particular business and in a particular trade.