The different layers of the Sun have different temperatures. For example, the surface of the Sun, the photosphere where the light comes from, is the coolest: 6000 degrees Kelvin, about 10,000 F. The core is about 27 million degrees Fahrenheit. Because we cannot go there with thermometer, this was derived from mathematical models.
For a picture and description, see the webpage
http://fusedweb.pppl.gov/CPEP/Chart_Pages/5.Plasmas/SunLayers.htmlMandy