The watt (symbol W) is the International System of Units (SI) measure of power, defined as one joule of energy transferred per second, and it quantifies the rate at which work is done or energy is consumed. In everyday life, watts rate the output of light bulbs, appliances, and electronic devices, while in scientific and engineering fields they describe the performance of engines, generators, and renewable‑energy systems such as solar panels and wind turbines. Understanding watts is essential for calculating energy costs, optimizing power efficiency, and comparing the capabilities of diverse technologies, making this unit a cornerstone of both practical household decisions and advanced technical analysis.