This forms the lowest layers of the Sun's 'atmosphere' which extends into the rarefied region known as the solar corona . The photosphere displays a number of interesting features, most of which are driven by the fundamental electromagnetic force of nature. Cooler regions of the photosphere are known as sunspots . These are produced when magnetic field lines break through the photosphere and cool the surrounding gas. Other magnetically driven phenomena are flares and prominences .
Flares occur above sunspots when the energy contained in the magnetic field is suddenly released.
This cause sub-atomic particles to be flung outwards at large fractions of the speed of light and all forms of electromagnetic radiation to be spontaneously released. Prominences form when magnetic fields lift gas into the chromosphere and drape it over their field lines. Sometimes this happens with leisurely quiescence and at other times it occurs on time scale of a minute or so. The photosphere, itself, is a dynamic place. Huge convective cells of gas rise and fall like boiling milk and the 'surface' undulates constantly.