Sunlight, in the broad sense, is the total spectrum of the electromagnetic radiation given off by the Sun. On Earth, sunlight is filtered through the atmosphere, and the solar radiation is obvious as
daylight when the Sun is above the horizon. This is usually during the hours known as day. Near the poles in summer, sunlight also occurs during the hours known as night and in the winter at the poles sunlight may not occur at any time. When the direct radiation is not blocked by clouds, it is experienced as sunshine, a combination of bright light and heat. Radiant heat directly produced by the radiation of the sun is different from the increase in atmospheric temperature due to the radiative heating of the atmosphere by the sun's radiation.
An area seen as a dark spot, in contrast with its surroundings, on the photosphere of the Sun. Sunspots are concentrations of magnetic flux, typically occurring in bipolar clusters or groups. They app
ear dark because they are cooler than the surrounding photosphere. Larger and darker sunspots sometimes are surrounded (completely or partially) by penumbrae. The dark centers are umbrae. The smallest, immature spots are sometimes called pores.
Sunspots are temporary phenomena on the photosphere of the Sun that appear visibly as dark spots compared to surrounding regions. Sunspots are caused by intense magnetic field, which inhibits convecti
on, leaving their temperature (~ 3000–4500 K) lower than the temperature of surrounding material ( ~ 6000) K and makes them visible as dark spots. Sunspot sizes vary from 16 km to 160,000 km in diameter. They usually appear as pairs, with each sunspot having the opposite magnetic pole than the other. Sunspots host coronal loops and reconnection events. Most solar flares and CMEs originate in magnetically active regions around sunspot groups.