Magnetic storms are caused by the Sun's hyperactive magnetic field moving and buzzing around the surface of the sun along with highly particles. This magnetic storms on the sun is what causes solar flares and sometimes CMEs (Coronal Mass Ejection) to happen.
The effects of solar flares and CMEs on Earth and life as we know it are minimal because the Earth is protected by a magnetic field. However, if we talk about electronics, then it is a different story. If a solar storm or a CME is to hit Earth, the Earth's magnetic field would be disturbed, causing a geomagnetic storm. It is this geomagnetic storm that causes auroras to show up in latitudes lower than it normally should. And finally, for electronics - from satellites, motherboards, transformers, computers and phone electronics - all of them would be fried. This kind of phenomena happened before, during 1859, or better known as the Carrington event, where a massive CME hit Earth, frying all sorts of electronics in North America and Europe at the time. Thankfully, we only have telegraph as a form of electronics back in the day.
