The solar equator completes one rotation in 25 days. The poles complete one rotation in 36 days. The collapse is stopped by internal pressure in the core of the star. During the collapse, the potential energy of infalling hydrogen atoms is converted to kinetic energy, heating the core. As the temperature goes up, the pressure goes up to stop the collapse.
Convection is the motion of heated material, such as bubbles in boiling water.
When the temperature is high and all the atoms are stripped of their electrons, the opacity is low and radiation transfer is dominant. When the temperature drops, such as in the outer layers of the solar interior, the protons and electrons recombine to form atoms and the opacity goes up. High opacity slows the transfer of energy by radiation, so bubbles form. These bubbles are hot and low in density, thus starting a convective flow. These 5 relationships, described as mathematical formula, show how energy is generated, how that energy effects the structure of the Sun and how that energy is transported to the surface to make the Sun shine.