"Watts per square meter" (W/m²) is a unit of measurement that indicates the amount of power (in watts) received or emitted per unit area (in square meters). It is commonly used in fields like physics, engineering, and environmental science to quantify energy transfer, such as solar radiation hitting a surface or heat flow through materials. This measurement helps in understanding energy efficiency and performance. For example, in solar energy applications, knowing the W/m² value of sunlight can help determine how much energy a solar panel can generate. Similarly, in building design, it can assess heat loss or gain through walls and windows.