A material fact is a piece of information that is significant or essential to a contract's terms, influencing the decision-making process of the parties involved. It is critical in determining whether a contract has been breached or if misrepresentation has occurred, as it relates to the facts that would affect a reasonable person's understanding of the agreement. In the context of misrepresentation and fraud, knowing what constitutes a material fact can significantly impact the validity of claims made during negotiations or execution of contracts.