Sunspots are associated with high magnetic fields that somehow keep the heat away. Sunspots usually appear in pairs or groups, with some spots of one magnetic polarity and the other spots of the other polarity. This is where flares, prominences and filaments occur. Flares are caused by a sudden release in the tension of all those mixed-up magnetic fields associated with the sunspots. The positive and negative magnetic fields readjust to a more simplified form and a great amount of energy is released.
Flares occur much more commonly during the maximum of the solar sunspot cycle.
Prominences and filaments are actually the same phenomenon, just viewed in a different way. It may have been labeled as a flare, but in fact, it is a lifting off of a cool region of neutral gas that's been hovering over neutral magnetic field areas. A filament is the same thing, but located on the face of the Sun, rather than the limb. You usually can't see the corona because the surface of the Sun is so bright. One of the big mysteries about the Sun is how the corona could get so hot when the surface of the Sun is so much cooler.