This document defines a contract and outlines key concepts in contract law including offer and acceptance, consideration, duties and enforcement, and defenses. It explains that a contract is a legally binding promise, and covers topics such as what constitutes a valid offer, how acceptance forms a contract, the need for consideration on both sides, the concept of substantial performance of duties, remedies for breach such as damages and specific performance, and defenses that can make a contract void like unconscionability, fraud, duress, and illegality.