This introductory chapter provides a brief overview of the fundamental elements of what constitutes a contract. It discusses undertakings or promises, deeds, written and oral promises, bargains, and bilateral and unilateral contracts. It concludes by examining some general themes in contract law to which reference will be made throughout the present title. These include freedom of contract, will theory, economic efficiency, objectivity in contract law, common law and equity, contract law within private law, and international influences on contract law. The outline provided in this chapter is necessarily brief; although some of the themes may seem a little difficult in the abstract, students approaching this subject for the first time should not be troubled. The concepts will become familiar and more easily understood through concrete examples provided in later chapters.