All of the sun's energy is generated in the core where it is about 15 million Kelvin. The energy is carried by radiation through the core, then through the other parts of the interior it is carried by convection. The outer layer of the sun is about fifty eight hundred Kelvin. The photosphere is the visible layer of the sun. Energy is moved to the photosphere by convection.
Convection is the transportation of energy as the hot matter moves up and the cool matter falls.
Granules form on the photosphere due to the convection process. The whole suns surface is oscillating. This oscillation is caused by the granules constantly moving. Because of the waves lengths of the granules on the photosphere we can tell information about different levels in the sun's interior. The chromosphere is not a spherical shell around the sun like most people would think, instead it has small spikes throughout it called spicules which rise and fall.