【正确答案】正确答案： Contract, in law, is an agreement that creates an obligation binding upon the parties thereto. The essentials of a contract are as follows: 1. mutual assent; 2. a legitimate compensation, which in most cases need not be pecuniary; 3. contracting parties who have legal capacity to make a contract; 4. no fraud or duress; 5. the subject of contract shall not be illegal or in violation of public norms. In general, contracts that can be either orally or be in writing. Some of the contracts, however, in order to be enforceable, must be written and signed.