Consideration is something of value that is exchanged between parties to a contract. It is essential for a valid contract. Consideration can be in the form of an act, abstinence from an act, or a promise. It must be something that moves from the promisee at the desire of the promisor. Consideration does not need to be adequate, but it must be real, lawful, and not something the promisor is already obligated to do. Without consideration, there is no valid contract, though there are some exceptions such as natural love and affection or compensation for voluntary services.