Sunspots; photosphere
When you look at the Sun through a filtered telescope, the visible portion of the Sun appears blotchy. These blotches are called sunspots. The layer of the Sun where these occur is called the photosphere.
Sunspots are dark cooler patches that show from time to time on the surface of the sun in a layer known as the photosphere. Sunspots are formed due to concentrations of magnetic field flux that hinders convection and have temperatures of about 3,800 degrees K while photosphere has a temperature of about 5,800 degrees Kelvin.