Unlike many of the other legal principles, contract law is a comparatively new area of law. There was a process during the Middle Ages when someone, usually a member of the nobility, could write down a promise and then “seal” the document with a wax impression created with a signet ring or other distinctive object that had a symbol such as a coat of arms. This process eventually reached the lower strata of society, and binding oneself “under seal” became the only kind of promise that was enforceable during that time.
During the seventeenth and eighteenth centuries, as a middle class developed in England (and later in the United States), and as commerce began to flourish, merchants began to require a way to enforce agreements without resorting to the cumbersome medieval notion of the “binding seal.” Instead, new understandings of the way that merchants dealt with one another came to be recognized by the courts, and a new area of law developed to meet the needs of those involved in mercantile dealings. Our modern capitalist society, of course, could not exist today without contracts. 
The law of contracts governs which agreements the law will enforce and those that it will not. This is important to the business of real estate because every real estate transaction involves a promise by at least one person to sell real property and a promise by someone else to buy it. As a real estate licensee, you will complete contracts day in and day out. It is important to understand how a contract is created, what makes a contract valid or invalid, and how a contract can be terminated or voided.
Every time you are involved in a real estate transaction, you will use a contract that transfers or indicates an interest in the property. It is important that you understand the nature of legal agreements so you are able to explain them to your clients and customers as part of your role as a real estate licensee.