The economic principle related to a property's most profitable use that is both legal and economically feasible is called the highest and best use. It is a concept used in real estate valuation that refers to the most profitable use of a property that is legally and physically possible, financially feasible, and maximally productive. The highest and best use of a property is determined by analyzing factors such as zoning laws, market demand, and physical characteristics of the property to determine the most profitable use of the land.