Quid pro quo ("something for something" in Latin[2]) is a Latin phrase used in English to mean an exchange of goods or services, in which one transfer is contingent upon the other; "a favor for a favor". Phrases with similar meanings include: "give and take", "tit for tat", "you scratch my back, and I'll scratch yours", and "one hand washes the other". Other languages use other phrases for the same purpose.
Common law
In common law, quid pro quo indicates that an item or a service has been traded in return for something of value, usually when the propriety or equity of the transaction is in question. A contract must involve consideration: that is, the exchange of something of value for something else of value. For example, when buying an item of clothing or a gallon of milk, a pre-determined amount of money is exchanged for the product the customer is purchasing; therefore, they have received something but have given up something of equal value in return.
