It may be a bilateral contract, performed by both parties, or unilateral, a promise in exchange for an act or performance of a task or deed. Contracts may be voided, that is, the parties may agree to nullify the contract or it may be voided by a court of law. These are some of the characteristics of a contract. Every good contract has four essential component parts. An offer is communicated verbally or in writing and has definite terms.
Mutuality indicates duties or actions are performed by each party.
Consideration means that something of value is exchanged. Competent parties speak to the mental and legal capacity of the parties involved in making the contract. A legal object connotes a legal objective and no criminal intent. It has no particular form. Written is better, though, then the terms are less often questioned.