Sunlight is a portion of the electromagnetic radiation given off by the Sun, in particular infrared, visible, and ultraviolet light. On Earth, sunlight is scattered and filtered through Earth's atmosphere as daylight when the Sun is above the horizon. When direct solar radiation is not blocked by clouds, it is experienced as sunshine, a combination of bright light and radiant heat (Atmospheric). When blocked by clouds or reflected off other objects, sunlight is diffused. Sources estimate a global average of between 164 watts to 340 watts per square meter over a 24-hour day; this figure is estimated by NASA to be about a quarter of Earth's average total solar irradiance.

धूप सूर्यकिरणों से सीधे प्रकाश और गरमी को कहते हैं। इसके अंतर्गत विकिरण के दृश्य अंश ही नहीं आते, वरन् अदृश्य नीललोहित और अवरक्त किरणें (infrared) भी आती हैं। इसमें सूर्य की परावर्तित और प्रकीर्णित किरणें सम्मिलित नहीं हैं।