The Sun's magnetic field lines get wound up due to its differential rotation, which means the surface moves at different speeds depending on latitude ^{1 2}. When the winding gets extreme, the magnetic field lines "snap," causing solar flares at those locations on the surface ¹. The "tangles" in the magnetic field lines can produce very strong localized magnetic fields, and places where "ropes" of bundled field lines "break" the surface of the Sun are active regions where sunspots form ². The solar wind flows outward from the Sun along open field lines, while closed field lines trap coronal plasma ^{3 4}.