This is a close-up of the Sun's photosphere, the outer shell of the Sun from where the visible light is radiated. We see a region with some sun spots recorded by the 1 metre Solar Telescope of the Royal Swedish Academy of Sciences on the island of La Palma. The image shows different convection cells or granules where hot plasma is rising at the centre of the cells (thus they have a brighter colour) and falling down on its edges (with a darker colour since it's cooler). Typically those granules have diameters of about 1000 km - so you could fit a whole country like Germany or France into one of these granules - and they last for about 15 minutes before they dissipate. At any given time there are about 4 million convections zones on the entire surface of the Sun.