Thermodynamic Equilibrium is a state in which a system's macroscopic properties, such as temperature, pressure, and volume, remain constant over time. In this state, there are no net flows of energy or matter within the system or between the system and its surroundings. This means that all parts of the system are in balance, and any changes that occur are uniform throughout. When a system is in Thermodynamic Equilibrium, it can be described by a set of thermodynamic variables that do not change. This concept is essential in understanding how energy is transferred and transformed in various processes, such as in engines or refrigerators, where maintaining equilibrium is crucial for efficiency.