The document discusses the definition and essential elements of a valid contract. It defines a contract as an agreement enforceable by law involving an offer, acceptance, consideration, and lawful object. It outlines the key elements that must be present for an agreement to constitute a legally binding contract, including offer and acceptance, intention to create legal relations, lawful consideration, capacity of parties, free consent, lawful object, certainty, possibility of performance, and avoidance of certain prohibited agreements. It also distinguishes between different types of contracts and agreements.