In physics, power is defined as the rate at which work is done or the rate at which energy is transferred. Quantitatively, it represents the amount of energy expended or delivered over a specified period of time. The standard international (SI) unit for power is the watt (W), which is equivalent to joules per second ($\text{J/s}$). Understanding power is critical for analyzing the efficiency of physical systems, whether they involve mechanical forces, electrical circuits, or thermal energy conversion. Mathematically, it can be determined by dividing the total work done by the time taken, providing a fundamental measure of the capacity or capability of a physical system to perform useful actions.